Guest Writer


Gast Schrijver



Dr. Pearl Chin



Neil Gordon
P.Eng, MBA

Chris Phoenix

CRN Director of Research

Rory McLean

Like Him, Hate him,
Kiss Him, Hug Him,

Dr. Jose Feneque, DVM

Associate Veterinarian, Crossroads Animal Hospital, Miami, Florida, USA



Alan Shalleck



CEO/President/Chairman of
Colossal Storage Corporation



Michael Anissimov

co-founder the Immortality Institute for Infinite Lifespans



Jason Des Forges

plenty of room
down there…
nano talk from
New Zealand



Sander Olson

Vice President of NanoApex Corp


K.P Merlinq

Merlinq in nanoland


Gina Miller


Ruud Smits

Department of Innovation Studies Utrecht University
The Netherlands


Darrell Brookstein

Investment executive


Mike Treder

Executive Director
Center for Responsible Nanotechnology the wave

nanotehnoloogia, nanoteknologia, nanotechnologija, nanotehnologijas, nanoteknologija, nanotechnologii, nanotecnologia, nanotehnologijo, nanoteknik

Reading Room - Lesezimmer - Leeskamer

Reading Room - Lesezimmer - Leeskamer


Professor, Meijo University and Director, Research
Center for Advanced Carbon Materials, National Institute of Advanced
Industrial Science and Technology (AIST

Nanotube and nanohorn
Future real key player of nanotechnology

"I really don't want people to exaggerate carbon nanotubes too much. I want them to leave the tubes alone a little more," says Prof. Iijima, the discoverer of carbon nanotubes. He now thinks that commercial applications of carbon nanohorns will be realized much earlier than those of carbon nanotubes.

Unlike carbon nanotubes, carbon nanohorns can be made simply without the use of a catalyst. Carbon nanohorn aggregates can be produced with a yield of more than 90% through laser vaporization of carbon at room temperature. These aggregates have a dahlia-like shape with a large number of horn-shaped short single-layered nanotubes that stick out in all directions. The tips of these short nanotubes are capped with five-membered rings. Carbon nanohorns' key characteristic is high adsorbability, due to their large surface area -- about 400 square meters per gram, but as Prof. Iijima says, "Adsorbed atoms tend to slip easily from the surface of the carbon nanohorns because of their complete graphite surface structure. To hold atoms on the carbon nanohorn surface, either the carbon nanohorns must be modified chemically or their structures must be partially damaged. Various potential characteristics of carbon nanohorns can be displayed by modifying their surface."

Researchers have high expectations for applying carbon nanohorns to fuel cells as their electrode material, among other applications under consideration. Fuel cell electrodes made of carbon nanohorns are expected to help improve the cells' power-generation capacity and extend their lifetime because platinum catalyst nanoparticles disperse among carbon nanohorns and do not aggregate. Carbon nanohorns are also expected as gas storage material, making use of their high adsorbability. Carbon nanohorns have for the first time cleared the United States Department of Energy threshold of commercial reality as methane gas storage material. Carbon nanohorns have also been found to selectively adsorb DNA fractions. Inorganic materials are now used in selecting DNA fractions. However, it is believed that carbon with a high biocompatibility may be a better material than inorganic substances. The Japan Science and Technology Agency (JST) has adopted a project to promote the application of carbon nanohorns in the biotechnology field as one of its "Solution Oriented Research and Technology" projects. This project started in January 2003 for a better understanding of the adsorption to carbon nanohorns, as well as for studying surface modification methods for controlling their selective adsorbability.

Prof. Iijima has not forgotten carbon nanotubes entirely; he has been studying how they grow. Carbon nanotubes will not be used commercially unless they can be mass-produced. He says, "Real nanotechnological progress is to develop nanomaterials, which can be used in fuel cells, field effect transistors and other useful products." Such developments have not been achieved yet at this stage. Prof. Iijima says, "People are exaggerating carbon nanotubes too much. However, I can say with confidence that carbon nanotubes have made great contributions to basic science." They do play a significant role in verifying the quantum effect. Prof. Iijima thinks that the real value of carbon nanotubes is their contribution to basic science.

He does not want to hear that what he has achieved in his research is the discovery of carbon nanotubes. He says, "I had conducted research using electron microscopy for 30 years before I discovered carbon nanotubes, so discovering them is just one of the results of my research based on electron microscopy." He obtained a Ph.D. in studying filament-shaped silver bromide. His experience conducting structural analyses at that time helped him find carbon nanotubes. He says, "When you do not have any clue as to how to start new research, you cannot rely on anyone but yourself. What you can rely on when you face a serious difficulty is nothing but your experience." This is his empirical rule.
(Interviewer: Kuniko Ishiguro, Cosmopia Inc.)

For more information,




Associate Professor, Catalysis Research Center,
Hokkaido University and Researcher, Precursory Research for
Embryonic Science and Technology (PRESTO), Japan Science and
Technology Agency (JST)

Fabrication of novel core-shell nanostructured materials using the size-selective photoetching technique

Surface coating of nanoparticles with different materials to produce
core-shell structures is currently an active area of research, because
such coating allows modification and tailoring of physical and
chemical properties of core materials depending on synthetic
conditions. Furthermore, core-shell nanoparticles are expected to have
unique properties that are not originally present in either core or
shell materials. In the present study, we attempt to fabricate the
novel core-shell structure of semiconductor nanocomposites using the
size-selective photoetching technique and apply them to develop new
catalysts, optoelectronic devices and sensors.

We have recently developed the size-selective photoetching technique
as a means of preparing monodisperse semiconductor nanoparticles. The
principle of this technique relies on two facts -- that metal
chalcogenide semiconductor particles are photocorroded, and that the
energy gap of size-quantized semiconductor nanoparticles increases
with a decrease in the particle size. If the irradiation is performed
with use of monochromatic light that can photoexcite the large
particles alone, these nanoparticles are selectively photoetched to
smaller ones until the irradiated photons are not absorbed in the
nanoparticles due to the size quantization effect.

With irradiation of monochromatic light, the diffuse reflectance
spectra of silica-coated CdS nanoparticles were blue-shifted, and
finally the absorption onset agreed well with the wavelength of
irradiation light. These results indicated that the large CdS
particles were photoetched to smaller ones until the irradiated
photons were not absorbed in nanoparticles. TEM observation revealed
that the monochromatic light irradiation caused a decrease in the size
of the CdS core particles but the shell structure seemed to be
unchanged, resulting in a void space formation between the photoetched
core particle and the shell. The void space could be adjusted by
choosing the wavelength of irradiation light. We call this structure a
"jingle-bell" nanostructure.

The void space in the core-shell nanostructure will be useful for the
purpose of applications, such as novel catalytic reaction sites and
fabrication of metal-semiconductor nanojunctions. Work in this
direction is currently in progress.

For more information,




Director-General/Professor, Institute for Molecular
Science, Okazaki National Research Institutes
Currently, Director,Wako Institute and Discovery Research Institute,
The Institute of Physical and Chemical Research (RIKEN)

Discovery of organic-metallic
multiple-decker sandwich clusters
" Opening up cluster chemistry

Prof. Koji Kaya, says, "I heard later that when I sent my first paper on this study to a scientific journal, the comments of the referees were divided. Some of them said it was a great work, while the others called it completely wrong." He looked back at the reaction when he announced his discovery of benzene-vanadium sandwich clusters.

At that time, an established theory in this field was that benzene with a stable molecular structure does not react with transitional metal, and therefore does not form any chemical bonds with such metals.

His new discovery completely overturned this theory. He was originally a chemist. He used to synthesize binary metal clusters, dimers and polymers. He started studying combinations of transitional metals and benzene with a simple molecular structure, believing that bonding organic chemicals and metals could create new, unique compounds. He began this research with studying the reaction between transitional metals with 3d-electrons and benzene through gas phase reactions. As a result, he discovered that sandwich clusters of benzene and a metal could be synthesized with metal atoms belonging to the scandium to chrome groups in the periodic table. He says, "When a transitional metal with d-electrons reacted with an aromatic compound, d-electrons and pi-electrons created bonding orbits, and these electrons moved freely within the orbits. This indicates that metal atoms and aromatic molecules became a single molecule. I was really excited about proving this phenomenon. When the magnetism of vanadium atoms inside the sandwich clusters was measured, their magnetic moment was found to have increased linearly as the number of metal atom is increased. When moveable electrons exist around a metal atom, these electrons interact with electrons of the next metal atom as if they are chatting with each other in the cluster. As a result, the spins of the metal atoms' electrons align in the same direction." Prof. Kaya's discovery that benzene-vanadium clusters have magnetism surprised researchers around the world.

Prof. Kaya started his career as a chemist by measuring the potential curve between mercury and rare gas atoms by bombarding mercury atoms with those of the rare gases. Since he has considered that periodicity is the basis of chemistry, he focused his attention on the magic number of valence electrons, and discovered metal clusters of NaAl13, which has an electronically stable structure. These clusters were formed by combining aluminum tridecamer having 39 valence electrons with sodium having a single valence electron, to bring the total amount of valence electrons to the magic number of 40.

He developed the so-called soft-landing technique, through which metal clusters can be piled up on a substrate without any fragmentation. He has been researching methods to put these clusters to practical use.

For him, metal clusters are now going from materials for clarifying properties to materials toward new catalysts and realization of novel optical properties.

Prof. Kaya is continually working to create new ideas. He says, "What I think I really need to do is to investigate what functions compounds associated with weak interactions will show in solution under certain conditions." His goal beyond this is to understand the mystery of life and contribute it to human happiness. He says, "I want to clarify theoretically information transmission, energy transfer and other mechanisms occurring continuously inside the human body through cooperation among researchers in physics, chemistry, biology and other fields." He adds that this kind of effort may in the long run lead to new cures for diseases. He says that nanotechnology should be used for human happiness in the 21st century.
(Interviewer: Shiro Saito, Cosmopia Inc.)

For more information,



Xiaobing REN

Senior Researcher, Materials Physics Group, National
Institute for Materials Science and Researcher, Precursory Research
for Embryonic Science and Technology (PRESTO),
Japan Science and Technology Agency (JST)

Exotic multiscale phenomena associated with nano-order of point defects

A huge class of materials exhibits spontaneous (automatic) ordering
with respect to atomic/ionic displacement or spin below a
characteristic temperature (Currie temperature); they are called
ferroic materials. Such ordering transitions (called ferroic
transitions) result in very interesting phenomena at three different
length scales simultaneously, from nano scale (atomic/ionic
displacement, spin, etc.), mesoscopic scale (domain), to macroscopic
scale (strain, electric effects, magnetic effects). On the other hand,
point defects (such as vacancies, impurities, doping elements, etc.)
are inevitable in these materials. Recently we found that the nano-
range distribution of these point defects possesses a general symmetry
property. This nano-ordering is expected to generate a wide range of
exotic multiscale phenomena in these transforming materials, such as
huge response in elasticity, piezoelectricity, and magnetism.

Recently, we clarified that the exotic multiscale phenomena exist in
martensitic alloys by observing the process of martensitic/reverse
transformation. However, it is not known whether these phenomena exist
in other materials, or whether novel properties predicted by the
phenomena will be discovered. If novel properties are discovered,
potential applications in various fields of science and engineering
are greatly expected.

Our present project is aimed at discovering these novel phenomena and
their underlying physical mechanisms. These new effects are also of
significant technological importance and may have potential
applications in novel actuators and sensors as well as magneto-electro
-mechanical devices.

For more information,



Executive Vice President,
Research and DevelopmentGroup, Hitachi Ltd.
(Currently, Chief Technical Officer, Automotive Systems, Hitachi, Ltd.)

Bridging the gap between technological
seeds and needs.

Devising a strategy to cross technology's death valley

Japan is thought to be a world leader in the field of nanotechnology.

But even in Japan, the so-called "Death Valley of Technology" lies between results of research and their commercialization. Hitachi Ltd. is devising various strategies to cross this abyss. Leading such efforts is the executive vice president of Hitachi's Research and Development Group, Dr. Hideyo Kodama, the company's chief strategist in the nanotechnology field.

In 2001, Nanotechnology R&D Promotion Center for the Hitachi Group was established by over ten Hitachi Group companies, and Dr. Kodama has since been general manager of the center. He explained the reasons for establishing the center by saying, "There are both potential users and developers of new nanotechnologies within the Hitachi group because group members include manufacturers and users of industrial materials.

The group established the R&D promotion center to strengthen its nanotechnology sector." Some Hitachi group laboratories have cooperated special projects being carried out in the fields of information technology/electronics, environment/energy, and medicine/ welfare. Researchers and other staff members participating in such projects use an effective information-sharing system designed to match technological "seeds" developed by project participants with technological needs of other participants. Developers of seeds usually cannot imagine all their potential applications. In the system, the seeds are spread by their developers to other participants by e-mail.

These messages stimulate project members to find potential applications of the new seeds. This system has greatly shortened the time needed between the development of technological seeds and the
realization of trial products based on the seeds.

Dr. Kodama says he plans to establish a technology platform. In April, 2003, his center established a platform for computational science designed in combination with measurement technologies to strengthen the group's computer-based simulation capability for developing new materials. The center has also been very active in forming partnerships with national laboratories and universities. It has already established such partnerships with 14 research bodies, to which Hitachi researchers are sent to discuss their projects.

Dr. Kodama says, "I think there used to be the idea among both university professors and companies that professors create new ideas and companies commercialize them. But now, both sides need to get closer to each other. I think this is the simplest approach for crossing the 'Death Valley.'" His center signed a partnership agreement with the Nanotechnology Research Center of Hokkaido University in April, 2003 as its latest cooperation with an outside research organization. They have kicked off a project to develop periodic nano-structures based on self-organization.

What specific areas is Dr. Kodama paying attention to in the widely diversifying nanotechnology field? "I'm interested in the environment.

When we think about the so-called 'Hydrogen Society' in 10 years, what technological problems related to industrial materials will we face and what kinds of materials will enable us to solve such problems? We have been discussing these issues." He says his center is studying a method to improve sharply the power generation efficiency of fuel cells by applying nanotechnology. He has confidence in the method, saying that he and his colleagues at the center will astonish the world when they unveil a trial product in fall, 2003.

(Interviewer: Kuniko Ishiguro, Cosmopia Inc.)

For more information,



Division Head, Department of Bioengineering,
National Cardiovascular Center Research Institute and Researcher,
Precursory Research for Embryonic Science and Technology (PRESTO),
Japan Science and Technology Agency (JST)

Development of a bioactive-material consisting of an inorganic nanoparticle-organic-cell composite

Germ infection through a percutaneous device has been very serious issue for long-term implantation in the body for such applications as artificial hearts, peritoneal dialysis and tube feeding. In this study, we are developing a percutaneous device for preventing germ infection by strong adhesion in the body.

The concept of the material is based on three elements:

I. Sintered hydroxyapatite (HAp) nano-crystal controlled the morphology: this shows high bioactivity and actual clinical results in dental and orthopedic fields.

II. Silk fiber: this has good mechanical strength, good stability in the living body, good molderability, and an actual clinical result as a surgical suture.

III. Fibroblast: this secretes collagen to construct an extra cellular matrix.There are covalent bonds between I and II, an anchoring effect between II and III, and good compatibility between III and I. The elements are in good harmony in thecomposite.

A novel inorganic-organic composite was developed consisting of HAp nanoparticles showing 50-200 nm prepared by an emulsion system and silk fiber with graft-polymer having the functional groups reacting covalently toward the HAp surface. The composite fiber showed good mechanical properties, just like non-treated fiber, and fibroblasts strongly adhered on the material.

We are trying to increase the collagen secretion from the cells on the material. The research is progressing with medical doctors in my facility, aimed at clinical application.

For more information,


Chris Phoenix

CRN Director of Research

The Bugbear of Entropy

Entropy and thermodynamics are often cited as a reason why diamondoid mechanosynthesis can't work. Supposedly, the perfection of the designs violates a law of physics that says things always have to be imperfect and cannot be improved.

It has always been obvious to me why this argument was wrong. The argument would be true for a closed system, but nanomachines always have an energy source and a heat sink. With an external source of energy available for their use, they can certainly build near-perfect structures without violating thermodynamics. This is clear enough that I've always assumed that people invoking entropy were either too ignorant to be critics, or willfully blind.

It appears I was wrong. Not about the entropy, but about the people. Consider John A. N. (JAN) Lee. He's a professor of computer science at Virginia Tech, has been vice president of the Association for Computing Machinery, has written a book on computer history, etcetera. He's obviously intelligent and well-informed. And yet, he makes the same mistake about entropy--not in relation to nanotech, but in relation to Babbage, who designed the first modern computer in the early 1800's.

In Lee's online history of Babbage, he asserts, "the limitations of Newtonian physics might have prevented Babbage from completing any Analytical Engine." He points out that Newtonian mechanics has an assumption of reversibility, and it wasn't until decades later that the Second Law of Thermodynamics was discovered and entropy was formalized. Thus, Babbage was working with an incomplete understanding of physics.

Lee writes, "In Babbage's design for the Analytical Engine, the discrete functions of mill (in which 'all operations are performed') and store (in which all numbers are originally placed, and, once computed, are returned) rely on this supposition of reversibility." But, says Lee, "information cannot be shuttled between mill and store without leaking, like faulty sacks of flour. Babbage did not consider this, and it was perhaps his greatest obstacle to building the engine."

Translated into modern computer terms, Lee's statement reads, "Information cannot be shuttled between CPU and RAM without leaking, like faulty sacks of flour." The fact that my computer works as well as it does shows that there's something wrong with this argument.
In a modern computer, the signals are digital; each one is encoded as a voltage in a wire, above or below a certain threshold. Transistors act as switches, sensing the incoming voltage level and generating new voltage signals. Each transistor is designed to produce either high or low voltages. By the time the signal arrives at its destination, it has indeed "leaked" a little bit; it can't be exactly the same voltage. But it'll still be comfortably within the "high" or "low" range, and the next transistor will be able to detect the digital signal without error.
This does not violate thermodynamics, because a little energy must be spent to compensate for the uncertainty in the input signal. In today's designs, this is a small fraction of the total energy required by the computer. I'm not even sure that engineers have to take it into account in their calculations, though as computers shrink farther it will become important.

In Babbage's machine, information would move from place to place by one mechanism pushing on another. Now, it's true that entropy indicates a slightly degraded signal--meaning that no matter how precisely the machinery was made, the position of the mechanism must be slightly imprecise. But a fleck of dust in a bearing would degrade the signal a lot more. In other words, it didn't matter whether Babbage took entropy into account or even knew about it, as long as his design could tolerate flecks of dust.

Like a modern computer, Babbage's machine was designed to be digital. The rods and rotors would have distinct positions corresponding to encoded numbers. Mechanical devices such as detents would correct signals that were slightly out of position. In the process of correcting the system, a little bit of energy would be dissipated through friction. This friction would require external energy to overcome, thus preserving the Second Law of thermodynamics. But by including mechanisms that continually corrected the tiny errors in position caused by fundamental uncertainty (along with the much larger errors caused by dust and wear), Babbage's design would never lose the important, digitally coded information. And, as in modern computers, the entropy-related friction would have been vastly smaller than friction from other sources.

Was Babbage's design faulty because he didn't take entropy into account? No, it was not. Mechanical calculating machines already existed, and worked reliably. Babbage was an engineer; he used designs that worked. There was nothing very revolutionary in the mechanics of his design. He didn't have to know about atoms or quantum mechanics or entropy to know that one gear can push another gear, that there will be some slop in the action, that a detent can restore the signal, and that all this requires energy to overcome friction. Likewise, the fact that nanomachines cannot be 100% perfect 100% of the time is no more significant than the quantum-mechanical possibility that part of your brain will suddenly teleport itself elsewhere, killing you instantly.

Should Lee have known that entropy was not a significant factor in Babbage's designs, nor any kind of limitation in their effectiveness? I would have expected him to realize that any digital design with a power supply can beat entropy by continually correcting the information. After all, this is fundamental to the workings of electronic computers. But it seems Lee didn't extend this principle from electronic to mechanical computers.

The point of this essay is not to criticize Lee. There's no shame in a scientist being wrong. Rather, the point is that it's surprisingly easy for scientists to be wrong, even in their own field. If a computer scientist can be wrong about the effects of entropy on an unfamiliar type of computer, perhaps we shouldn't be too quick to blame chemists when they are likewise wrong about the effects of entropy on nanoscale machinery. If a computer scientist can misunderstand Babbage's design after almost two centuries, we shouldn't be too hard on scientists who misunderstand the relatively new field of molecular manufacturing.

But by the same token, we must realize that chemists and physicists talking about molecular manufacturing are even more unreliable than computer scientists talking about Babbage. Despite the fact that Lee knows about entropy and Babbage did not, Babbage's engineering was more reliable than Lee's science. How true it is that "A little learning is a dangerous thing!"

There are several constructive ways to address this problem. One is to continue working to educate scientists about how physics applies to nanoscale systems and molecular manufacturing. Another is to educate policymakers and the public about the limitations of scientific practice and the fundamental difference between science and engineering. CRN will continue to pursue both of these course



Director/Professor, Nanotechnology Research
Center, Research Institute of Electronic Science, Hokkaido
University and Team Leader, Frontier Research System, The Institute
of Physical and Chemical Research (RIKEN)

Fabrication of patterned film by self-organization -Utilization of the bottom-up approach
dependent on natural phenomena-

The regular convection seen in a hot miso soup (Benard convection), wine droplets forming on the edge of a wine glass (fingering instability), stains formed in concentric layers in a coffee cup that was purposely allowed to sit for several days (stick-slip motion)_$B!D_(Ball of these patterns form on their own. Prof. Shimomura directed his attention to the fact that in complex systems, these patterns are self -organized based on the rules of non-equilibrium thermodynamics.

By simply evaporating polymer solutions on a substrate, Prof.
Shimomura succeeded in fabricating films that have ordered structures such as dot, line-patterned or honeycomb structure. For this purpose, two glass plates were first set one on top of the other. By putting a polymer solution with a constant concentration into the space between the two plates, a uniform pattern can be formed. Because self- organization in dissipative structures is not so dependent on molecular structure, it can be applied to various polymeric materials to form patterns. The biggest benefit of this patterning technology is that compared to lithography, the process of creating the patterns can be greatly simplified. The process is also energy- and cost-efficient.

Currently, the minimum unit size of the patterned films is around 200 to 300nm. For Prof. Shimomura, the target is to reduce this to less than 100nm. "If we can reduce the unit size to less than 100nm, the scope of application of this technology will be significantly expanded, " says Prof. Shimomura. He now faces the challenge of making a completely uniform pattern along with enhancing the reproducibility and also miniaturizing the patterns. The honeycomb-patterned polymer film fabricated using this method is expected to have potential applications in regenerative medicine. "When liver cells are cultured on a flat film, the cells also tend to flatten. Cells in this form do not function properly. However, when liver cells are cultured on a honeycomb-patterned film made by utilizing self-organization, a number of the cells assemble, take on a spherical shape, and come to express the function of the liver." Even when using films made from the same material, the form and the function of the cultured cells can be altered depending on the structure of the film.

In 2002, the Hokkaido University Nanotechnology Research Center was established. Prof. Shimomura, who played a role in its opening, is now the center's director. Says Prof. Shimomura, "In order to further proceed with the research on nanotechnology, we need to have a global vision and realize collaborations that go beyond the boundaries of the current academic fields. In order to do this, we need to develop a good system." The Nanotechnology Research Center was completed on November 27, 2003 on the northern campus of Hokkaido University. The site was originally appointed as a place to promote the Joint Research Project and is now being developed to become the center of intelligence for the creation of a new industry. Furthermore, the Nanotechnology Research Center is a key member of the 21st Century Center of Excellent Project for Advanced Life Science on the Base of Bioscience and Nanotechnology, meaning that an environment for developing young researchers is about to be created.

"The research on nanotechnology is not just a one-time trend,"
emphasizes Prof. Shimomura. "The European researchers are describing nanotechnology as a 'renaissance in science technology.'" In this so- called renaissance, Prof. Shimomura points out that a strict definition of terminology is necessary. "Originally, there was no discipline in the world of science, but then it gradually got more and more subdivided. In the nano world, researchers talk to each other going beyond the walls of discipline. However, we sometimes find out that same words are used differently depending on the research field you are in. For instance, there is a slight difference in the nuance when I use the word 'self-organization' and when a researcher in physics uses it. By clarifying what the difference is, we should be able to get new inspirations and findings." Prof. Shimomura expects younger generations of researchers to overcome the boundaries between different fields and cultivate a new domain. "I want the young people to be flexible in their way of thinking and act as interpreters between the different fields."
(Interviewer: Yu Tatsukawa, Cosmopia Inc.)

For more information,



Associate Professor, Department of Molecular and
Material Sciences, Kyushu University and Researcher, Precursory
Research for Embryonic Science and Technology (PRESTO), Japan
Science and Technology Agency (JST)

Surface structure determination
and development of low-energy electron
diffraction for small surface regions

Determination of surface structures is the initial stage in
understanding surface properties. I have studied relatively complex
structures, including the surface reconstruction of substrates by low-
energy electron diffraction (LEED) and scanning tunneling microscopy
(STM). Cu(001)-(4x4)-Li is one of the typical structures. We have
determined atomic positions with an accuracy of better than 0.01 nm
using LEED analysis. The best-fit model consists of four Li adatoms
and six substituting Li atoms. In an STM image, although we could not
distinguish individual Li atoms, we could observe four Li adatoms as
one protrusion. Since we know the surface crystal structure in the
unit cell, we could make a detailed atomic arrangement, including
steps and defects. Recently we have been studying mixed ordered
structures formed by coadsorption of two different elements.

On the other hand, the usual diffraction method cannot be used to
study nanometer-scale structures or small domain structures, which
makes it very difficult to learn the atomic arrangements of such
structures. Convergent-beam electron diffraction in transmission
electron microscopy has great potential for use in determining the
structures of small regions, but it is applicable only to thin films.
Low-energy electron microscopy is also a marvelous technique. It can
be used to obtain diffraction patterns from regions as small as 100 nm.
I would like to obtain LEED patterns from even smaller regions, for
instance 10 nm, and I am trying to develop a new LEED apparatus using
STM tips as a field emission gun. Although certain diffraction
patterns have not been obtained yet, elastically scattered electrons
have been detected. To obtain sharper electron beams, improvement of
the tips is being planned.

For more information,



Yoshio BANDO

Director, Advanced Materials Laboratory, National
Institute for Materials Science (NIMS)

Exploring new nanoscale materials
The world's smallest thermometer brought by serendipity and an inquisitive spirit

The "carbon nanothermometer" that Dr. Bando discovered is ranked as the "smallest thermometer" in the Guinness Book of Records. A gallium filling in a carbon nanotube of 85 nm in diameter expands in proportion to temperature. Dr. Bando's enthusiasm for studying new nano structures led to the accidental discovery that was destined to happen.

Initially, he focused on making nanotubes from GaN as a blue LED material. The idea was to grow the nanotubes out of GaN produced by flowing nitrogen gas at 1360 degree C over amorphous carbon particles and gallium oxide, but in fact the carbon nanotubes grew on the gallium particles. "When I observed them with an electron microscope, I found that depending on how the electron beam was irradiated, the gallium in the carbon nanotube expanded or shrank." This phenomenon is explained by the change in the temperature of the gallium. The possibility of measuring temperature over a range from 50 degree C to 500 degree C with an accuracy of 0.25 degree by maximizing the resolution of an electron microscope has since been confirmed. The technique was first made public in the February 2002 issue of "Nature"
and was recognized as the world's smallest thermometer.

Dr. Bando specializes in electron microscopy. When he started off as a scientist around 1975, he came across the most-advanced ultra-high voltage electron microscope. He says, "It might have been the best electron microscope at the time, but it was only being used to observe atomic arrangements. It was more important to identify atoms and analyze the bonding states of atoms." He went to the U.S. where research on analytical electron microscopes was just beginning, and developed his first analytical electron microscope in 1984.
Furthermore, he developed a field-emission electron microscope with improved spatial resolution of electron spectrometry by reducing the diameter of the beam spot to 0.4 nm in 1993.

In the year 2000, he developed the world's most powerful atom- discriminating electron microscope, which is now used to identify atoms and analyze electron states by separating electrons that have lost energy (inelastically scattered electrons) and electrons that have retained energy (elastically scattered electrons) by using an omega-type energy filter in the microscope cylinder. By using such spectrometry to achieve atom discrimination with the spatial resolution of 0.5 nm, he was the first to observe the periodic structure of oxygen atoms in AlN.

Currently, his research using electron microscopes is mainly focused on BN nanotubes. He initially succeeded in creating nanocables with metallic nanowires in BN nanotubes, and discovering BN nanocones with the tip angle of 39 degree and BN fullerene cages. He has found that the BN fullerenes consist of five-membered rings and four-membered rings so far.

Although he describes his great discoveries as "unexpected discoveries, true serendipity", they were the direct result of his efforts. "Only a researcher with appropriate knowledge and experience can see through a phenomenon. A researcher's capability should be judged by his ability to see through things."
(Interviewer: Shiro Saito, Cosmopia Inc.)

For more information,



Associate Professor, Department of Material
Chemistry, Graduate School of Engineering,
Kyoto University and Researcher,
Precursory Research for Embryonic Science and Technology
(PRESTO), Japan Science and Technology Agency (JST)

Design and application of materials
with hierarchical pore structure
via liquid phase process

Supramolecular templating of nano-pores in inorganic-based materials
has been becoming popular recently. There exists, however, a difficult
step if one tries to construct macroscopic devices that make the best
use of such templated pores. The author and his colleagues have
developed a so-called "top-down" liquid phase processing of
hierarchical pores consisting of well-defined macropores and templated
(not yet highly ordered) nano-pores.

When the polymerization-induced phase separation and sol-gel
transition take place concurrently, spinodal decomposition may occur,
generating a transient multiphase structure characterized by "co-
continuity" of the respective phases. By freezing the transient co-
continuous structure within the gel through the irreversible sol-gel
transition, a well-defined macroporous structure can be easily
obtained after the removal of the volatile components. The median pore
size can be controlled by adjusting the onsets of phase separation and
sol-gel transition.

Surfactants that have supramolecular templating ability can be used to
induce the phase separation in the sol-gel process based on the
hydrolysis of metal alkoxides. The co-continuous gel skeletons then
contain a sub-structure consisting of templated structural units of
the gel phase. Upon removal of the templating molecules by thermal
decomposition or solvent extraction, sharply distributed nano-pores
are obtained without influencing the pre-formed macroporous framework.

Materials with such hierarchical pore structures exhibit a superior
efficiency and lower pressure resistance than those of conventional
particle-packed devices. Pure silica gels with hierarchical macropores
and nano-pores have been applied to the highly efficient monolithic
HPLC column, and its capillary version also appears on the market.
Catalyst-loaded columns that polymerize monomers and in parallel
partition the products by molecular mass are now under investigation.
Widespread possibilities of the monolithic highly efficient support
material are to be found in every industrial field that has utilized
solid-liquid contact devices consisting of particle-packed structures.

For more information,



Kazunobu TANAKA

Board trustee, National Institute of Advanced Industrial Science
and Technology (AIST)

Four suggestions for developing nanotechnology
as a key industry in Japan
Based on experience conducting atom technology project

A project initiated in 1992 was carried out for the upcoming era of nanotechnology in Japan. The project focused on atom technology, a type of nanotechnology with emphasis on the bottom-up approach. This project, whose aim was partially to merge semiconductor technology and biotechnology, was conducted at the Joint Research Center for Atom Technology (JRCAT), where about 100 researchers from the business, academic and government sectors were brought. Dr. Tanaka was responsible for this project and served as a project leader for 1997- 2002.

This project comprised four focused areas. -- identification and manipulation of atoms and molecules; formation and control of nanostructures on the surface and at the interface of materials; spin electronics; and theoretical analysis of the dynamic processes of atoms and molecules. Completed in March 2002, the project generated many results that have contributed significantly to the establishment of the present nanotechnological foundation in Japan.

Dr. Tanaka strongly requested universities to participate in the project. Behind his strong desire was his successful experience as the leader of an earlier research project in which his project group developed amorphous silicon solar cells. Dr. Tanaka attributed one of the reasons for the success of the project to the participation of university teams.

In the atom technology project, he also wanted to conduct research at a single laboratory at which many researchers from various fields could gather. He says, "All research groups of the project not only worked closely with each other in the facility but also shared the same cafeteria and relaxation room. This sounds like a very simple child's play. But the effectiveness of this method, designed to promote the integration of groups from various research fields at a faster pace, has been proved at the Max Planck Institute for Solid State Physics, Stuttgart, Germany and other research institutes."

Dr. Tanaka has made four suggestions for the successful consolidation of research from different fields, as follows:

1) "A higher investment priority should be put on research proposals that appear to help develop a new research field based on a wide range of the present sectors," he says. He adds that it is important to encourage researchers to integrate their own expertise with that of their counterparts in different fields. Inter-ministry joint research projects being studied by the Council for Science and Technology Policy, Japan, are examples of his suggestion and will start from the coming FY 2004.

2) It is important to create an environment in which -- more than in other research circumstances -- researchers are highly likely to meet each other. Namely, researchers from different fields should have their own offices closely located on the same floor of the same building or share the same office. It effectively accelerates cross- disciplinary interaction between researchers and groups, which has been historically evidenced by several institutes as mentioned above.
Dr. Tanaka also created such an environment in JRCAT, as he has explained.

3) Active use of sabbatical leaves. Dr. Tanaka says it is important to provide researchers with a period of six months to one year during which they can reconfirm the positioning of their own studies in society. Such a break is necessary once for every six to seven years to give researchers a "bird's eye view" of their work.

4) University curriculums should be flexible enough to respond quickly to changing times and to meet current social needs.

Dr. Tanaka says nanotechnology in Japan will not make any progress unless project leaders and researchers with a wide outlook are brought up. He adds that the master plan for developing nanotechnology in Japan should be discussed from the mid- and long-term viewpoint by young researchers with strong physical and intellectual ability.

(Interviewer: Kuniko Ishiguro, Cosmopia Inc.)

For more information,



Tadaaki NAGAO

Associate Professor, Surface/Interface Science
Division, Institute for Materials Research, Tohoku University

Sheet plasmon and electron dynamics in
low-dimensional matter

The impact of plasmons in materials science has been increasing, as
seen in their application in surface-enhanced Raman scattering (SERS),
gas and bio-sensors and photonic materials. These kinds of well-known
applications mainly utilize "surface plasmon", which are mainly
characterized by bulk properties, and is limited to the visible light
range. On the other hand, plasmons confined in low-dimensional
metallic systems have steep dispersions and a wide spectral range from
far-infrared to ultraviolet waves and expected to have wide

In this project, I will study the dynamical aspect of low-dimensional
metallic systems in the "momentum-energy space" by using a high
momentum-resolution energy-loss-spectrometer (ELS-LEED) that has
recently been developed. For example, the experiment and analysis of
the plasmon in a dense 2D electron system in a surface-state band on
silicon have revealed that this particular system behaves like an
ideal 2D free-electron system because of its high electron density.
Also, plasmon dispersion curves for a quasi-2D interface plasmon mode
in metallic nanofilm were measured for the first time for a perfectly
flat self-organized Ag nanofilm on a silicon substrate.

By accumulating novel information of plasma dynamics in prototypical
low-dimensional metallic systems, I will correlate the transport/
optical properties in low-dimensional materials. Via this kind of
physical approach, the guiding principle for designing novel classes
of functional materials based on low-dimensional conductive phases
will be established.

For more information,

Masayoshi ESASHI

Professor, New Industry Creation Hatchery Center,
Tohoku University

Creating next generation industry
based on 'NEMS technology'
Combining micromachining with nanomachining.

A slender catheter equipped with a sensor at its tip is inserted through a blood vessel to measure the pH of blood. Development of this semiconductor ion sensor for medical use by Prof. Esashi opened up a new world of micromachining research in Japan.

In the mid 70s, Prof. Esashi was a graduate student at Tohoku University when he developed a semiconductor ion sensor (ISFET) for medical use, using MOS transistors that were used for electric calculators. He was working with Prof. Jun-ichi Nishizawa who was a leader of Japanese semiconductor researches at that time. Later, he developed miniaturized technology for pressure and acceleration
sensors and advanced technology in packaging that was important for devices applicable to practical uses. Prof. Esashi also developed original micromachining equipment and has been leading a way in pioneering research in the micromachining field. Micromachining is the technology based on silicon microfabrication technology and a combination of various technologies such as electronics, mechanics, optics, and material science. This technology has been utilized for the production of various microelectromechanical systems (MEMS) that
are key components for information/communication systems, electric appliances for automobile/home, and medical/biological devices. Currently, Prof. Esashi is making efforts to combine micromachining with nanomachining because "The combination of micromachining and nanomachining will enable us to construct sensors and systems with higher performance and better quality than the existing MEMS." He aims at developing MEMS into NEMS (nanoelectromechanical systems) by applying nanomachining.

One of his remarkable achievements is the electron beam source for a lithography system that enables the fabrication of high performance VLSIs: it allows direct and maskless patterning narrower than 100 nm. It consists of deposited carbon nanotubes with nanomachining at the tips of a silicon needle array that has been prepared with micromachining. Another one is the next generation high-density data storage device with multi-nanoprobes. The device consists of 32 x 32 arrayed probes with nano heater tips each. A recording media is heated by the tips and data is written onto the medium at a density of as high as 1 Tb / inch^2. The stored data are read out by using the conductivity difference of a single digit between the heated portions and unheated portions.

Prof. Esashi's research theme, researches toward practical use, is based on the Tohoku University's traditional philosophy, "Jitsugaku" or practical science. He suggests "the small volume production of multiple kinds of high-value-added products using high technologies" to utilize our own technological skills and know-how for national industrial recovery. He also suggests the joint industry-university
research based on "open collaboration" to make our industries more internationally competitive. Nanomachining can be applied in various fields.

Prof. Esashi always makes his standpoint clear by saying; "Providing industry with 'NEMS technologies' information that industry needs is the role of university researchers." Indeed, there are many visitors from private companies to share information with him. "Our job is to open up a new field into which no one has been. Therefore, our efforts could go wrong. What is important here is to find out what went wrong. Learning from failure will lead you to further research." adds Prof. Esashi.

(Interviewer: Shin Chikushi)

For more information



Associate Professor, Research Center for Quantum
Effect Electronics, Tokyo Institute of Technology

Nanofabrication process for semiconductors
using atomic force microscope


Scanning probe microscopes (SPMs), such as scanning tunneling microscopes (STMs) and atomic force microscopes (AFMs), are now routinely used as tools not only for observing surfaces but also fabricating nanoscale structures. Currently, technology using SPMs is attracting considerable attention as a new nanolithography method.

In the work, an AFM tip-induced direct nano-oxidation method has been developed to fabricate nanoscale p-GaAs oxide dots and wires. The remarkable point of this study is that the heavily carbon-doped GaAs, which shows semi-metal conduction, was oxidized using this method. Furthermore, the oxidized material is easily etched by water. Therefore, by adjusting both oxidation and etching process conditions, a groove with 40nm width and 6nm depth was successfully fabricated.

GaAs is a well-known material for the fabrication of semiconductorheterostructures, and InAs quantum dots are easily grown on the GaAs substrate. Therefore, this AFM-based oxidation process is directly applicable to the development of nanoscaled semiconductor devices. We are now trying to achieve the positioning of InAs quantum dots by using AFM-oxidized patterned GaAs substrates.

For more information



Satoshi KAWATA

Professor, Applied Physics, Graduate School of
Engineering, Osaka University
and Chief Scientist, Nanophotonics Laboratory,
The Institute of Physical and Chemical Research (RIKEN)

Beyond the diffraction limit
Photonics explores the nano world

The world's smallest bull, which will appear in next year's Guinness Book of World Records, is 8 mm in length and 5mm in height. The legs, horns, and the tail are so small as to be beyond the diffraction limit and can not be imaged by visible light. The bull's body is made from photopolymerizable resin, a polymer that solidifies by absorption of light. Prof. Kawata has developed a nanophotonics method to manipulate nanoscale structures using an ultrafast femtosecond laser of several
hundred nm wavelength.

When photons are strongly confined both temporally and spatially, two photons can simultaneously excite an electron in a target. The femtosecond laser has made this strong confinement possible. A 1kW peak power femtosecond laser compresses energy into a 100fs pulse so that strong confinement is achieved with an exposure of only 1mW near infrared light for 10ns. When this compressed pulse meets the resin target, the multiphoton process is confined to the region of high
photon density and solidification occurs only at the focal point. Nanodevices can be developed from this new method, completely different from the conventional method of "cutting". The micro-bull is proof indeed.

Femtosecond lasers have also proved to be very powerful as a tool for biology. Since a cell is transparent, a femtosecond laser beam can propagate through the interior of a cell without damaging the surface and manipulate only the subcellular organelles at the focal point. Photonics is becoming indispensable in the field of biology, as well as the more conventional semiconductor applications.

Another field of photonics research that Prof. Kawata is active in is the optical near-field. He has observed DNA and carbon nanotubes by near-field microscopy based on Raman scattering where the light spectra is shifted by molecular vibrations in the sample. The ability to simultaneously observe and analyse the sample is one primary aim of photonics. Prof. Kawata aims to develop optical microscopy that can observe the vibrations of single molecules. "I am still in the world of 10nm; I intend to go into the world smaller than 1nm to really see what is there. I intend to observe DNA in its natural state, without cutting or using chemical preparations. I have the ideas for how to get there and I think I will be able to reach it within a few years."

Prof. Kawata has been the Director of the Handai Frontier Research Center (FRC) at Osaka University since October 2001. The FRC has established the e-learning nano-engineering program within FRe-University for people who are now working in related fields. "Those with science or engineering degrees have never taken nanotechnology class at university before, and even people with non-science or engineering degrees can now learn nanotechnology. Take DNA as an example; it cannot be categorized precisely as biology, chemistry or physics. Nanotechnology explores not just a single field but a combination of cutting-edge science." Along with pursuing great advances in science, he also realizes the necessity of bringing
nanotechnology to the wider society.

(Interviewer: Kuniko Ishiguro, Cosmopia Inc.)

For more information

Takaaki KOGA

Researcher, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) and Visiting Scientist, Materials Science Research Laboratory, NTT Basic Research Laboratories

Control and applications of novel spin
properties found in
semiconducting nano structures

Researcher, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) and Visiting Scientist, Materials Science Research Laboratory, NTT Basic Research Laboratories

Electrons have spin degree of freedom in addition to charge degree of freedom. It is the charge degree of freedom that various conventional electronic devices to date have been based on. The ultimate purpose in the new research area of semiconductor spintronics is the development of electronic devices that actively utilize the spin degree of freedom of electrons in order to realize functionalities
that have never been realized in conventional electronic devices.

What I specially focus on in my PRESTO research is the gate-control of the spin properties in semiconductor heterostructures. Electron spins, which areexemplified by small magnets, have conventionally been controlled by externally applied magnetic fields. Although it had also been proposed that electron spins could be controlled by an electric field (via so-called Rashba spin-orbit interaction) instead
of a magnetic field, the main accomplishment in my PRESTO research includes the quantitative clarification of the gate-controlled Rashba spin-orbit coupling using the weak antilocalization analysis as itemized below:

(1) We performed a quantitative analysis on the weak antilocalization phenomena that are observed in a magneto-resistance at low temperatures in the InAlAs/InGaAs/InAlAs quantum well system. We then discovered an existence of zero-field spin-splitting in this system, which should be caused by the asymmetry in the potential shape of the quantum wells. The magnitudes of the spin splitting energies turned out to be consistent with those predicted in theory.

(2) We showed, theoretically, that a spin filter device can be realized using a triple barrier resonant tunneling structure. This spin device is composed of InGaAs and InAlAs for the well and barrier layers, respectively. These are both nonmagnetic materials, hence proposing a spin filter device without the use of any magnetic

(3) We examined a spin interference effect in a square loop array that is nanolithographically fabricated on an InAlAs/InGaAs/InAlAs quantum well heterostructure.

Regarding the above item (3), recent experimental results showed that the magnitude of the self-interference of the electron wave function varies as a function of the gate voltage. This result indicates that the electron wave function interferes with itself constructively or destructively depending on the value of the applied gate voltage, which supports the fact that spin precession angle is controlled by the magnitude of the spin-orbit interaction.

For future projects, I would like to make every effort, on the basis of the academic results accumulated to date, in experimental realization of the proposed spin filter device that utilizes resonant tunneling structure, as well as exploration of new research areas such as the examination of the relation between spin-orbit effect and phase relaxation time in a two-dimensional electron gas system.

For more information


Chris Phoenix

Director of Research CRN

Science and Technology:
The Power of Molecular Manufacturing

So what's the big deal about molecular manufacturing? We have lots of kinds of nanotechnology. Biology already makes things at the molecular level. And won't it be really hard to get machines to work in all the weirdness of nanoscale physics?

The power of molecular manufacturing is not obvious at first. This article explains why it's so powerful--and why this power is often overlooked. There are at least three reasons. The first has to do with programmability and complexity. The second involves self-contained manufacturing. And the third involves nanoscale physics, including chemistry.

It seems intuitively obvious that a manufacturing system can't make something more complex than itself. And even to make something equally complex would be very difficult. But there are two ways to add complexity to a system. The first is to build it in: to include lots of levers, cams, tracks, or other shapes that will make the system behave in complicated ways. The second way to add complexity is to add a computer. The computer's processor can be fairly simple, and the memory
is extremely simple--just an array of numbers. But software copied into the computer can be extremely complex.

If molecular manufacturing is viewed as a way of building complex mechanical systems, it's easy to miss the point. Molecular manufacturing is programmable. In early stages, it will be controlled by an external computer. In later stages, it will be able to build nanoscale computers. This means that the products of molecular
manufacturing can be extremely complex--more complex than the mechanics
of the manufacturing system. The product design will be limited only by

Chemists can build extremely complex molecules, with thousands of atoms
carefully arranged. It's hard to see the point of building even more complexity. But the difference between today's chemistry and programmable mechanochemistry is like the difference between a pocket calculator and a computer. They can both do math, and an accountant may be happy with the calculator. But the computer can also play movies, print documents, and run a Web browser. Programmability adds more potential than anyone can easily imagine--we're still inventing new things to do with our computers.

The true value of a self-contained manufacturing system is not obvious at first glance. One objection that's raised to molecular manufacturing is, “Start developing it--if the idea is any good, it will generate valuable spinoffs.” The trouble with this is that 99% of the value may be generated in the last 1% of the work.

Today, high-tech intricate products like computer chips may cost 10,000 or even 100,000 times as much as their raw materials. We can expect the first nanotech manufacturing systems to contain some very high-cost components. That cost will be passed on to the products. If a system can make some of its own parts, then it may decrease the cost somewhat. If it can make 99% of its own parts (but 1% is expensive), and 99% of its work is automated (but 1% is skilled human labor), then the cost of the system--and its products--may be decreased by 99%. But that still
leaves a factor of 100 or even 1,000 between the product cost and the raw materials cost.

If a manufacturing system can make 100% of its parts, and build products with 100% automation, then the cost of duplicate factories drops precipitously. The cost of building the first factory can be spread over all the duplicates. A nanofactory, packing lots of functionality into a self-contained box, will not cost much to maintain. There's no reason (aside from profit-taking and regulation) why the cost of the factory shouldn't drop almost as low as the cost of raw materials. At that point, the cost of the factory would add almost nothing to the cost of its products. So in the advance from 99% to 100% self-contained manufacturing, the product cost could drop by two or three orders of magnitude. This would open up new applications for the factory, further increasing its value.

This all implies that a ten billion dollar development program might produce a trillion dollars of value--but might not produce even a billion dollars worth of spinoffs until the last few months. All the value is delivered at the end of the program, which makes it hard to fund under American business models.

A factory that's 100% automated and makes 100% of all its own parts is hard to imagine. People familiar with today's metal parts and machines know that they wear out and require maintenance, and it's hard to put them together in the first place. But as nanoscientists keep reminding us, the nanoscale is different. Molecular parts have squishy surfaces, and can bend without breaking or even permanently deforming. This requires extra engineering to make stiff systems, but diamond (among other possibilities) is stiff enough to do the job. The squishiness
helps when it's time to fit parts together: robotic assembly requires less precision. Bearing surfaces can be built into the parts, and run dry. And because molecular parts (unlike metals) can have every atom bonded strongly in its place, they won't flake apart under normal loads like metal machinery does.

Instead of being approximately correct, a molecular part will be either perfect--having the correct chemical specification--or broken. Instead of wearing steadily away, machines will break randomly--but very rarely. Simple redundant design can keep a system working long after a significant fraction of its components have failed, since any machine that's actually broken will not be worn at all. Paradoxically, because the components break suddenly, the system as a whole can degrade gracefully, while not requiring maintenance. It should not be difficult
to design a nanofactory capable of manufacturing thousands of times its own mass before it breaks.

To achieve this level of precision, it's necessary to start with perfectly identical parts. Such parts do not exist in today's manufacturing universe. But atoms are, for most purposes, perfectly identical. Building with individual atoms and molecules will produce molecular parts as precise as their component atoms. This is a natural
fit for the other two advantages described above—programmability, and self-contained automated manufacturing. Molecular manufacturing will exploit these advantages to produce a massive, unprecedented, almost incalculable improvement over other forms of manufacturing.

To donate to the Center for Responsible Nanotechnology, go to, click on "D


Dr. Mae-Wan Ho

The Quantum Information Revolution

Quantum information processing takes advantage of some strange properties of the quantum world that have been known for more than a century. Dr. Mae-Wan Ho unravels some of the mysteries.

In 1948, Claude Shannon discovered how to quantify information as binary ‘bits’ – a ‘1’ or ‘0’ – which can represent any number, or combinations of logical operations. This started the ‘information technology revolution’ that has lasted close to fifty years, with exponential growth in computing power, referred to as ‘Moore’s Law’: the doubling in the number of components representing bits that can be packed on a chip every year or two.

But Moore’s Law is rapidly approaching its limits as bits are now shrunk to the size of molecules in the emerging field of molecular electronics (see "Nanotubes highly toxic", SiS 21). Does that mean computing power will have reached its limit or can there be a totally different approach that could allow us to jump over that barrier to much faster, more powerful and infinitely more efficient computing? The answer for the moment is a very excited yes possibly, by means of a literal quantum leap to quantum information processing, taking advantage of the properties of superposition and entanglement of quantum systems (see "How not to collapse the wave function", this series, for definitions).

Thus, photons, electrons or qubits (see below) that have interacted with each other, retain an exquisite organic connection. So, measuring the spin state of one entangled particle, for example, allows one to know that the spin state of the other is exactly in the opposite direction. Moreover, on account of quantum superposition, neither the measured particle, nor its entangled partner has a single spin direction before being measured, but is simultaneously both spin-up and spin-down.

Quantum entanglement allows qubits that are separated by great distances to interact instantaneously (or nonlocally).Entanglement has been demonstrated repeatedly in experiments, and is currently being exploited for quantum cryptography and quantum computing.Quantum computing For a quantum system, the fundamental unit of information is a quantum bit, or ‘qubit’ (see "Quantum computer, is it alive?" ISIS News 2001, 11/12). Qubits can be represented by alternative states of a photon’s polarisation, or an electron’s spin, and can be prepared in a coherent superposition of states of 1 and 0:??› = a?0› + b?1› (1)Here, a and b are the ‘complex quantum amplitudes’ (expressed in complex numbers) which when squared, gives the classical probabilities, upon measurement, of finding the system in a ?0› or a ?1› state.

This is only one bit of information, but because the amplitudes are continuous, they carry an infinite amount of information, similar to analogue information carriers such as the continuous voltage stored on capacitors.Quantum bits offer much more also on account of quantum entanglement. In a classical analogue system, one needs N capacitors to store N continuous voltages.

But a quantum system with N qubits, in the most general case, is a superposition of 2N states each with its own quantum amplitude.A collection of qubits can therefore store exponentially more information than a comparable collection of classical information carriers. All the N qubits in the system are entangled or inseparable. It is this entanglement that give quantum computing its power, at least in principle.

Quantum information processing requires qubits to behave as quantum memories for long-term storage, and for many applications to behave as quantum transmitters for long-distance communication. It was thought that cold and localized individual atoms are the natural choice for qubit memories and sources of local enanglement for quantum information processing, while individual photons are the natural choice for communication of quantum information, as they can travel large distances through the atmosphere or optical fibres with minimal disturbance.But whether an actual quantum computer can be built is very much debated. There are many obstacles to overcome, a major one being the loss of quantum coherence, which would destroy quantum superposition and quantum entanglement that quantum computing depends on; and the larger the number of qubits involved, the bigger the problem.

Apart from these engineering problems of implementation that have been mentioned, could there be a deeper problem that a quantum computer is like an organism, and shares with it the important property that as such, it is radically incontrollable and hence unable to serve our instrumental purposes (see "Quantum computer, is it alive?" ISIS News 2001, 11/12 )?Quantum communication and quantum crytographyImagine that two parties, A and B, or Alice and Bob, share two entangled qubits, say a pair of photons, that are perfectly correlated, so the photons can both only be in the 0, or in the 1 state.Before Alice or Bob measures her or his photon, the entangled pair of photons is in a superposition of the two (classically) mutually exclusive states.

But as soon as either does a measurement, the state of the other photon will be instantaneously determined. The entangled pair has equal probability of being measured 0 or 1. According to classical information theory, a string of random 0 and 1 carries no information. But, correlated random strings are just the crytographer’s dream, as they provide the one-off key for decoding information that can be changed with each message.Quantum crytography was first described in 1984 by theoretical physicists Charles Bennett of IBM’s Thomas J. Watson Research Centre in Yorktown Heights, Hew York and Gilles Brassard of the University of Montreal in Canada. And it goes like this.Supposing Alice and Bob share a series of entangled photons. Alice and Bob agree beforehand that a horizontal polarization corresponds to a ‘0’ and a vertical polarization to a ‘1’, and make a similar decision for the two diagonal polarizations, left or right. And suppose that Alice does the measurement before Bob.

Now, Bob can either look to see whether the photon he receives, after Alice has measured its entangled twin, is horizontally or vertically polarised by performing one measurement, or he can see whether it is left or right polarized by performing another measurement, but he cannot do both. So when the photon arrives at Bob’s, he randomly chooses to do the up- down measurement or the left-right (diagonal) measurement.

If Bob makes a diagonal measurement, the photon lies exactly midway between vertical or horizontal. And if Alice has made the measurement for up-down polarization, then there is fifty-fifty chance for Bob’s photon to be left or right polarised.At the end of the transmission of all the photons, Bob will know he has, by random chance, correctly measured

the polarizations of about half of all the photons, but doesn’t know which ones. Bob contacts Alice on a channel that does not have to be secure, say, by telephone, and tells her which type of measurement he has made for each photon. Alice replies to tell Bob which measurements were correct (the same as the ones she made). They discard the discordant ones and keep the rest for their key.To make sure that an eavesdropper, Eve, isn’t listening, Alice and Bob sacrifice a small number of their key to check it over the public channel for errors. If Eve has been snooping, and assessing the polarisation of the photons passing between Alice and Bob, she will have changed the polarisation of about half of them. Alice and Bob will notice this immediately.

That is the ideal scenario. In practice, the distance that the entangled photons that make up the key can be transmitted is more of a problem. For example, noise in the channel through which the photons pass will introduce a small number of errors, so a clever eavesdropper will measure such a small number of photons that Alice and Bob will not be able to tell whether the discrepancy is due to errors or eavesdropping. Though, under such circumstances, Alice and Bob can generate a new key by simply applying an algorithm to their existing key. So Eve, who is missing the bulk of the original key, cannot hope to predict the outcome of the algorithm.

There is yet another complication. It is possible for Eve to carry out ‘weak’ measurements that will not change the polarisation of the photons she is snooping on (see "How not to collapse the wave function" this series).In 1989, a team led by Bennett and Brassard built a working device, and sent photons through the air to a receiver about 30 centimetres away. By the mid-1990s, other groups were sending encrypted keys through tens of kilometres of optical fibre. In October 2001, a team of physicists at the University of Geneva in Switzerland launched a company called id Quantique, which will supply a system integrating the crytography hardware – photon sources and detectors, and fibre-optic connections – needed to exchange keys.

In March 2002, they used the system to send single photons through 67 km telecommunication cables running under Lake Geneva. " The system is very stable, and has the potential to be very fast." Said Nicolas Gisin, a member of the team.MagiQ Technologies, a New York firm that specializes in quantum technologies, is building another system, that like id Quantique, connects users linked by a single dedicated fibre. Other groups are working on systems that can support a network of users. In September 2001, BBN Technologies, based in Cambridge, Massachusettes began a five-year collaboration with teams at Boston and Harvard univerties to build a quantum network connecting the three institutions. Photons will be routed round the network using mirrors, "which send the photons along without measuring them".Another problem is that reliable single photon generators are not yet commercially available. Today’s system, such as those developed by id Quantique, use lasers that generate pulses so weak that they almost never contain more than one photon. But at such low intensities, nine out of ten attempts to fire a photon fail.Photon detection is also difficult.

To spot a single photon, the detectors must be so sensitive that they will sometimes register photons that are not there. Even then, they will typically miss 90% of all the transmitted photons. What’s more, many photons are absorbed by the optical fibre and never make it to receiver. Out of some 5 million bits per second sent, somewhere between 100 and 1 000 bits per second is received. But even this is enough for cryptography. The Advanced Encryption Standard, the encryption algorithm used by the US government, uses a key with a maximum of 256 bits. A key distribution that send 500 bits per second would allow users to change the key roughly twice per second, which is ample for most purposes.The distance that the key can be transmitted is a more important technical limitation.

Most experts believe Geneva’s group demonstration of 67 km transmission through telecommunication cable is near the limit, although transmission along optical fibre could be some 100 km. Another possibility considered is transmission through space, and eventually via satellite. Physicists have been able to transmit quantum keys for cryptography over distances of 23.4 kilometres in free space, but all these involved only single photons, not entangled pairs of photons.In June 2003, a new distance record was broken.

Markus Aspelmeyer and colleagues at the University of Vienna, Austria, showed it is possible for two photons to travel a total of 600 metres through free space and still remain entangled. The previous record for entanglement in free space was a few metres.The Vienna group used a crystal with nonlinear optical properties to split photons with a wavelength of 405 nanometres into pairs of entangled photons with wavelengths of 810 nanometres. These photons then passed through optical fibres to telescopes that focussed them onto a second pair of telescopes. One receiving telescope was 500 metres away on the opposite side of the river Danube, while the other was about 150 metres away. By comparing the photons detected by the two receiving telescopes, the team confirmed that the photons had remained entangled over a distance of 600 metres in free space.

There was no direct line of sight between the receiving microscopes.Quantum teleportationQuantum teleportation was discovered by Charles Bennett in 1993. Teleporting ordinarily means sending matter instantaneously through empty space, rather in the manner of Captain Kirk’s request: "Beam me up, Scotty", in the StarTrek television series. But quantum teleporting is less dramatic, it describes the transport of a quantum state from one place to another, without actually transporting material. It is an alternative way of transmitting quantum information.Imagine Alice and Bob already in possession of a pair of entangled qubits or photons.

If Alice prepares another photon (to be teleported) in a certain quantum state, she can pass this quantum state onto Bob by performing a measurement of a joint property of the two photons in her possession that will transform Bob’s qubit into one of four states, depending on the four possible (random outcomes) of Alice’s measurement. Alice’s measurement entangles the two photons in her possession, and disentangles Bob’s photon, thereby steering it into a certain state. Alice then communicates the outcome of her operation to Bob. In this way, Bob knows how to transform his photon into the quantum state of Alice’s photon. Alice and Bob have effectively used their shared entangled state as a quantum communication channel to destroy the state of a photon in Alice’s part of the universe and recreate it in Bob’s part of the universe.

Who wants quantum cryptography?

Physicists want it as an intellectual challenge, that much is obvious. But who will benefit? Organisations obsessed with secrecy will be the first to want to use quantum cryptography for transferring information within a single city, such as government offices, banks and businesses. In the longer-term, the military and big governments will probably be the most dedicated customers. Don’t forget, terrorist groups, too, could use quantum cryptography to plan their activities and escape ‘intelligence’.Or maybe no one can prevent clever snoopers using weak measurement to spy and get all the secrets.This is perhaps the best argument for total transparency in the coming quantum world.

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Akihisa INOUE

Director/Professor, Institute for Materials Research,
Tohoku University

"Metallic Glass"
opens a new field in materials science
--Development of new light-weight,
high-strength materials-

Prof. Inoue developed "metallic glass" having excellent mechanical
properties, e.g., high tensile strength and large elastic strains, and
he is currently a leader of worldwide researchers in materials science.
It has been generally known that, when solid lacks a systematic
atomic arrangement, that is, when it is in an amorphous state, its
strength and corrosion resistance are enhanced. People had believed,
to make an amorphous alloy, the rapid cooling of the molten alloys is
required and thus it is quite difficult to obtain amorphous alloys in
bulk. Contrary to this widely conceived belief, Prof. Inoue succeeded,
for the first time in the world, in developing metallic glass which
makes it possible to prepare bulk amorphous alloys without rapid
cooling. The papers published by him and his colleagues about their
discoveries have been highly evaluated by other researchers. Indeed,
the number of their citations is ranked at the highest level, and Prof.
Inoue has been awarded many prizes for his many discoveries including
the Japan Academy Award in 2002.

In 1982, Prof. Inoue became a research fellow at AT&T Bell
Laboratories (currently Lucent Technologies, Bell Laboratories), and
there, met Dr. Chen who had discovered a glass-transition phenomenon
in metals. This led Prof. Inoue to develop an interest in the
structural relaxation phenomena observed among non-equilibrium
materials. From then on, his study on the structural relaxation and
glass transition of non-equilibrium materials advanced steadfastly.
During the course of his study, he came to conceive the belief, "if it
were possible to reveal the principle governing the formation of a
glassy metal which exhibits a glass-transition phenomenon and
supercooled liquid state, it would be possible to produce bulk
amorphous alloys."

When a liquid material is cooled very rapidly, it does not crystallize
even when it is cooled below its freezing point, and maintains its
liquid state, which is called a supercooled state. When Prof. Inoue
began to study metallic supercooled liquids, he decided to reveal the
principle underlying the phenomena, and studied to obtain reliable
thermodynamic data related to the phenomena. In 1987, he found an
alloy having a wide temperature range in which a supercooled state is
maintained. This discovery stimulated his interest in developing bulk
amorphous alloys. In 1988, Prof. Inoue found a Zr-based alloy which
maintains a supercooled state down to a temperature equal to 60% of
the freezing point even when cooled at a rate as slow as 10 K/sec, and
then solidifies as glass. This alloy exhibits markedly different
mechanical properties depending on its microscopic structure: the
crystallized alloy is broken to pieces when hit with a hammer, but the
glassy alloy is quite resistant to the same impact. This glassy alloy
was a "bulk metallic glass" that Prof. Inoue had sought. This new
alloy was found to have excellent mechanical properties. It exhibited
ideal superplasticity. It had a tensile strength three times as high
as that of the crystalline alloys that had the same Young's modulus.
It also had an elastic elongation at least five times as high as that
of conventional crystalline alloys. The elastic energy the glassy
alloy could store just before it reached a yield point was twenty
times or more as high as that of conventional crystalline alloys.
Prof. Inoue reported his discoveries at some meetings in Japan. At
that time, his papers did not attract much attention from the audience.
This was probably because people confounded the metallic glass he had
discovered with an amorphous metal. However, the situation changed
dramatically when the results were made public to scientists around
the world.

In 1993, five years after Prof. Inoue's publication of Zr-based
metallic glasses, a group of researchers in the USA who had secretly
traced his research, published their discovery of a metallic glass
obtained from a beryllium-based alloy system, which in turn suddenly
ignited the interest of researchers in metallic glasses. By that time,
Prof. Inoue had discovered several hundreds of kinds of metallic
glasses, and in 1994 he deduced, from the observations accumulated
during the course of his study, empirical rules determining the glass-
forming ability of an alloy which are now called "Inoue's three
empirical rules." Based on these rules, Prof. Inoue further continued
his search for new metallic glasses, and added new alloys to a list of
metallic glasses he had prepared. Establishment of these empirical
rules is based on his enthusiasm towards finding a fundamental concept
applicable to all materials having a glass-forming ability and thus
profitable to all materials scientists interested in metallic glasses
around the world, rather than being based on a simple desire to devise
a method for finding a new resource of metallic glasses.

Metallic glasses having a thickness ranging from 1 to 100 mm have been
fabricated by employing various casting processes appropriate to the
alloy systems. Indeed, the face plate of a golf club made of a
metallic glass has been put to practical use. Currently, Prof.
Inoue's interest has shifted to nanostructured bulk alloys with high
strength and toughness, and his studies in this field also lead
materials scientists around the world. He carries out research on
strengthening of materials by crystallizing metallic glasses partially.
That is, bulk metallic glasses are partially crystallized by adding a
small amount of elements that do not satisfy the Inoue's empirical
rules into conventional metallic glass systems. The partially
crystallized metallic glasses have nanoscale crystals with a diameter
of 1 nm or more in their glassy matrix. This nanostructural feature
is responsible for the improved tensile strength and toughness of
these new alloys.

Prof. Inoue predicts confidently, "Maybe in ten years the metallic
glasses we have developed will be used as a basic material for
nanotechnology because of their excellent viscosity, fluidity and
workability. This is because there are no metallic materials that are
more readily amenable to fine processing than these metallic glasses."

Interviewer, Shin Chikushi


Yasunori TODA

Associate Professor, Department of Applied Physics,
Hokkaido University and Researcher, Precursory Research for
Embryonic Science and Technology (PRESTO), Japan Science and
Technology Agency (JST)

Quantum mechanical control of quantum dots by using coherently controlled light

One of the fascinating characteristics of quantum dots is their atomic-like discrete density of states with large energy-level spacing, in which acoustic phonon-mediated scattering should be suppressed compared with higher-dimensional structures. As a consequence, excitons in quantum dots are expected to exhibit long coherence time, which is advantageous for application of quantum information
processing. In such quantum logic devices, it is important to coherently control quantum units individually.

Our research aims at quantum mechanical control of exciton wavefunctions by using coherently controlled light. Because laser light exhibits high coherence, we can easily manipulate its waveform by a dispersion-free 4-f optical system in conjunction with a spatial light modulator (SLM), which alters the spectral phase of the pulse. By optimizing the excitation pulse, we can address the exciton
wavefunctions in individual self-assembled quantum dots (SAQDs).

We here used the sample of SAQDs. In a photoluminescence (PL) spectrum of the sample, several sharp emission lines originating from different SAQDs are observed. For the selective excitation, we optimized the excitation pulse based on the photoluminescence excitation (PLE) resonances. A contour plot of the PL spectra as a function of the phase of SLM shows normalized PL intensities at two peaks with fitting of the data by a sinusoidal function. Both peaks show oscillatory
behavior as a consequence of the quantum interference of the wavefunctions in each excited states. Furthermore we can address the exciton wavefunctions even in the collective excitation. This indicates the feasibilities for selective coherent control of individual exciton wavefunctions.

For more information,


Seigo Tarucha

Professor, Department of Physics, Graduate School of
Science, The University of Tokyo

Quest for quantum computing

"Even in the field of quantum mechanics, simple problems can be solved." Just as Prof. Tarucha says, the electron state of a single atom in a vacuum, for example, can be described by a simple Schrodinger equation, which can be solved. However, in order to understand the electron state of a system consisting of many atoms such as a solid, various interactions and external disturbances should be taken into
consideration, thus making it complicated problems to describe the phenomena.

"Interesting macroscopic phenomena, such as superfluidity of helium and superconductivity, tend to be derived from interactions among many particles. As a result of these interactions, quantum effects appear as macroscopic phenomena, and this is why we can utilize these quantum effects. However, I must say that there is a big gap between understanding of the micro-world that can be accurately
described by quantum mechanics, and the macro-world." In order to solve the complicated many-body problem, Prof. Tarucha fabricated an artificial atom. He was the first person in the world to do this.

An artificial atom is disk-shaped, and several hundred angstroms in diameter. This is 1000 times larger than a real atom. Electrons within artificial atoms are confined strongly in the vertical direction by a semiconductor heterostructure, and weakly in the in-plane direction by an electrostatic potential. When electrons are injected into the artificial atom one by one, the quantum confinement effect makes the
electrons in the artificial atom show a shell structure, and they have energy levels similar to those of electrons in a real atom. Prof. Tarucha fabricated the artificial atoms, which require extremely precise control in the semiconductor process, and then established the methods of analyzing phenomena in artificial atoms. He has also verified the basic assumption in quantum mechanics that had been
derived from empirical rules, using artificial atoms. That is to say, he succeeded in verifying Hund's rule, the Pauli exclusion principle, and the Tomonaga-Luttinger theory, and observing a novel Kondo effect.

"Conducting researches on physics for scientific purpose is of course important, but I also want to skillfully control the phenomena that have been elucidated by the physical researches and realize interesting applications of the findings. One example of such efforts is the quantum computer that utilizes the quantized spins." In
December 2001, IBM carried out quantum computing that uses the nuclear spins of molecules in a test-tube, and succeeded in detecting the results with NMR.

However, Prof. Tarucha is still determined to aim at quantum computing using solid-state devices." I cannot discard the thought of controlling the quantum state of electrons within solid. When performing basic experiments for quantum computing, solution- and atom/molecule-based systems are good for experimental research on
quantum computing but they are unfit for integration. I feel it important to implement a research that would at some point lead to some device, or be helpful to develop devices."

Prof. Tarucha also says that he does not have enough confidence to declare at this point that it is worth conducting R&D of quantum computing. But many researchers believe that it is worth conducting research on quantum computing and are striving to make progress in their research. "Of course, I also believe that quantum computing is meaningful. Many unknown physical phenomena are related to quantum
computing, and elucidating those unknown physical phenomena will lead to realization of quantum computers. Combining quantum bits is just a technical issue, so there is not much that people like us can do there. But when it comes to explicating the quantum coherence and entanglement state within a solid matter where complex quantum interactions exist, and also using them efficiently, there is much for us to research. We have an interesting world ahead of us."

(Interviewer: Kuniko Ishiguro, Cosmopia Inc.) the wave


Chihaya ADACHI

Associate Professor, Department of Photonics Materials Science,
Chitose Institute of Science and Technology and Leader,
"Construction of organic semiconductor laser and clarification of
device physics," Core Research for Evolutional Science and
Technology (CREST) Project "Construction of super high-speed, super
power-saving, high-performance nanodevice system," Japan Science and
Technology Agency (JST)

Organic electronics and photonics

Since the 1980's, research on organic semiconductors, both low molecular materials and polymers, has progressed, because of their unique electronic properties different from those of inorganic semiconductors, leading to novel optoelectronic applications.

Our research is now focused on electronic and optical properties of organic semiconductors that are open to novel optoelectronic applications, Organic LED, FET, solar cells and laser diodes. Through material design and synthesis, and new device architectures, we are aiming at realizing new organic devices and establishing device physics of organic semiconductors.

Recently, we clarified detailed exciton decay processes of electrophosphorescence. Photoluminescence of Ir(ppy)3 shows unique emission characteristics due to strong interaction between the central Ir and the ligands. It is independent of temperature, suggesting internal phosphorescence efficiency of 100%. We have also realized
injection of very high current density over 1000A/cm^2 into organic thin films. While it has been considered hard to inject high current density exceeding 1000A/cm^2, we have demonstrated that the injection of high current density is possible for organic thin films, which will open a way to realize organic laser diodes in the near future.

We are also interested in annihilation processes of molecular excitons, Triplet-Triplet, Singlet-Single and Exciton-Charge carrier under high current density. the wave


Dr. Zvi Yaniv

CEO of Applied Nanotech, Inc.

The New Nanotech Divide

Nanotechnology and nanosciences will undoubtedly change the world. Despite the bombastic financial and research reports, few people seem to have much of a grasp of what nanotechnology encompasses and how this new field will achieve the predicted dramatic results it promises. Unfortunately, the majority of nanotechnology enthusiasts fail to differentiate nanotechnologies that are imminent with those that are highly speculative or will be achieved in a very long term.

Nanotechnology, to differentiate from the internet revolution, stresses technology itself. As a result, the new field will be judged in ways that are fundamentally different from the Internet, which was evaluated in terms of traditional markets, selling products to consumers, etc.

Nanotechnology will affect almost every aspect of our lives - from health to energy, the food we eat, the water we drink, automobiles, buildings, clothes, etc. This revolution will be gradual over many years, with disruptive changes occurring sporadically, initially at a slow rate and then occurring more frequently with time.

Nanotechnology will be a global phenomenon. Governments in USA, Europe and Far East are increasing nanotechnology funding at unprecedented rates. However, it is essential to distinguish between the long-term benefits and the mainstream applications of nanotechnology, which are more interesting to industrialists and investors in the near and medium terms. Failure to distinguish between what is important now and what is theoretically possible some time in the future will separate the winners from the losers. Today this is the main reason and the source of misconceptions about nanotechnology.

Nanotechnology heavily depends on complex sciences and industries. In many cases this will result in longer time to market and as a result will require a lot of patience. On the other hand, the success of nanotechnology will be less susceptible to economic fluctuations because it is visionary in nature. In any case, it is widely recognized that those who do not keep up with nanotechnology developments will end loosing in a big way.

Just as the digital divide created two classes in the world economy, the nanotechnology divide will further accentuate and define the new knowledge-based industrial community.

Dr. Zvi Yaniv is CEO of Applied Nanotech, Inc, a subsidiary of Nano-Proprietary, Inc. (OTC Bulletin Board: NNPP). Through Applied Nanotech, Nano-Proprietary has an extensive intellectual property portfolio in the field of nanotechnology and a well-trained and well-managed nanotechnology research and development team. Their patent portfolio includes multiple fundamental claims for carbon nanotubes field emissions cathodes, which enables the company to further control critical components of nanotechnology, and advance its commercial vision of the technology. Currently Applied Nanotech is in advanced development for the application of electron emitting carbon nanotubes cathodes in a number of areas, including large area color televisions, new lighting devices, x-ray, and microwave generators.

This article is published courtesy of Nano Express

... read the article

Chris Phoenix

Center for Responsible Nanotechnology (CRN)

Science and Technology: Nucleic Acid Engineering

The genes in your cells are made up of deoxyribonucleic acid, or DNA: a long, stringy chemical made by fastening together a bunch of small chemical bits like railroad cars in a freight train. The DNA in your cells is actually two of these strings, running side by side. Some of the small chemical bits (called nucleotides) like to stick to certain other bits on the opposite string. DNA has a rather boring structure,
but the stickiness of the nucleotides can be used to make far more interesting shapes. In fact, there's a whole field of nanotechnology investigating this, and it may even lead to an early version of molecular manufacturing.

Take a bunch of large wooden beads, some string, some magnets, and some
small patches of hook-and-loop fastener (called velcro when the lawyers aren't watching). Divide the beads into four piles. In the first pile, attach a patch of hooks to each bead. In the second pile, attach a patch of loops. In the third pile, attach a magnet to each bead with the north end facing out. And in the fourth pile, attach a magnet with the south end exposed. Now string together with a random sequence of
beads--for example

1) Hook, Loop, South, Loop, North, North, Hook.If you wanted to make another sequence stick to it, the best pattern
would be:

2) Loop, Hook, North, Hook, South, South, Loop. Any other sequence wouldn't stick as well: a pattern of:

3) North, North, North, South, North, Loop, South
would stick to either of the other strands in only two places.

Make a few dozen strings of each sequence. Now throw them all in a washing machine and turn it on. Wait a few minutes, and you should see that strings 1) and 2) are sticking together, while string 3) doesn't stick to anything. (No, I haven't tried this; but I suspect it would make a great science fair project!)

But we can do more than make the strings stick to each other: we can
make them fold back on themselves. Make a string of:
N, N, N, L, L, L, L, H, H, H, H, S, S, S and throw it in the washer on permanent press, and it should double over.

With a more complex pattern, you could make a cross:NNNN, LLLLHHHH, LNLNSHSH, SSLLNNHH, SSSS The NNNN and SSSS join, and each sequence between the commas doubles over. You get the idea: you can make a lot of different things match up by selecting a sequence from just four letter choices. Accidental
matches of one or two don't matter, because the agitation of the water will pull them apart again. But if enough of them line up, they'll usually stay stuck.

Just like the beads, there are four different kinds of nucleotides in the chain or strand of DNA. Instead of North, South, Hook, and Loop, the nucleotide chemicals are called Adenine, Thiamine, Guanine, and Cytosine, abbreviated A, T, G, and C. Like the beads, A will only stick to T, and G will only stick to C. (You may recognize these letters from the movie GATTACA.) We have machines that can make DNA strands in any desired sequence.

If you tell the machine to make sequences of ACGATCTCGATC andTGCTAGAGCTAG, and then mix them together in water with a little salt, they will pair up. If you make one strand of ACGATCTCGATCGATCGAGATCGT--the first, plus the second backward--it will double over and stick to itself. And so on. (At the molecular scale, things naturally vibrate and bump into each other all the time; you
don't need to throw them in a washing machine to mix them up.)

Chemists have created a huge menu of chemical tricks to play with DNA. They can make one batch of DNA, then make one end of it stick to plastic beads or surfaces. They can attach other molecules or nanoparticles to either end of a strand. They can cut a strand at the location of a certain sequence pattern. They can stir in other DNA sequences in any order they like, letting them attach to the strands. They can attach
additional chemicals to each nucleotide, making the DNA chain stiffer and stronger.

A DNA strand that binds to another but has an end hanging loose can be peeled away by a matching strand. This is enough to build molecular tweezers that open and close. We can watch them work by attaching molecules to the ends that only fluoresce (glow under UV light) when they're close together. A motor that goes around in circles in either direction, in controllable steps, depending on which strands are mixed in next, has also been built.

(The first URL has a neat animation of how the tweezers work.)

Remember that DNA strands can bind to themselves as well as to each other. And you can make several strands with many different sticky sequence patches to make very complex shapes. Just a few months ago, a very clever team managed to build an octahedron out of only one long strand and five short ones. The whole thing is only 22 nanometers wide--about the distance your fingernails grow in half a minute.

So far, this article has been a review of fact. This next part is speculation. If we can build a pre-designed structure, and make it move as we want, we can--in theory, and with enough engineering work--build a molecular robot. The robot would not be very strong, or very fast, and certainly not very big. But it might be able to direct the fabrication of other, more complex devices--things too complex to be built by pure
self-assembly. And there's one good thing about working with molecules:
because they are so small, you can make trillions of them for the price of one. That means that whatever they do can be done by the trillions--perhaps even fast enough to be useful for manufacturing large
products such as computer chips. The products would be repetitive, but evenrepetitive chips can be quite valuable for some applications.
Individual control of adjacent robots would allow even more complex systems to be built. And with a molecular-scale DNA robot, it might be possible to guide the fabrication of smaller and stiffer structures, leading eventually to direct mechanical control of chemistry--the ultimate goal of molecular manufacturing.

This has barely scratched the surface of what's being done with DNA engineering. There's also RNA (ribonucleic acid) and PNA (peptide nucleic acid) engineering, and the use of RNA as an enzyme- or antibody-like molecular gripper. Not to mention the recent discovery of RNA interference which has medical and research uses: it can fool a cell into stopping the production of an unwanted protein, by making it think
that that protein's genes came from a virus.

Nucleic acid engineering looks like a good possibility for building a primitive variety of nanorobotics. Such products would be significantly less strong than products built of diamondoid, but are still likely to be useful for a variety of applications. If this technology is developed before diamondoid nanotech, it may provide a gentler
introduction to the power of molecular manufacturing.

... read the article

Toshio KIMURA,

Fellow and General Manager, Central Research
Institute, Mitsubishi Materials Corporation

Creation of new functional materials utilizing nanotechnology

-- Heading for higher-value-added material --

From "business in tons" to the "business in grams"; electronic materials such as semiconductors have changed the values of the materials business. Progress in the area of high-value-added and highly functional materials has created a new industry.

This movement has been supported by material manufacturers. Mr. Kimura initially specialized in plastic forming, and later got involved in research on technology for producing jet engine materials, aluminum cans and copper pipes. He now is leading a research group that is taking up the challenge of creating high-value-added materials utilizing nanotechnology.

The main purpose for Mr. Kimura and his research group is the development of functional materials. One function that can be gained by breaking down materials into nanoparticles is transparency. Powder consisting of particles smaller than 50nm shows increased transparency, because less light is scattered as the diameter gets smaller.

The research group focused on this point, and expanded the types of material fabricated into nanoparticle powder, from silica to alumina, and then to titanium oxide, together with commercializing these transparent powders. Titanium oxide is ordinarily white powder, but becomes more transparent as the particle size decreases to nano-size. When it is used in foundation, the skin exhibits clarity and has UV protection.

"We have been expanding the application of nanoparticles from powders to particle dispersion liquid and films" says Mr. Kimura.

Two processes can be used to produce nanoparticles: the liquid phase process (wet process), and the vapor process (dry process).

Normally, nanoparticles are in large agglomerated particles immediately after
production. Thus, the most critical step in the process of making particle dispersion liquid from powder is loosening the aggregate into fine particles to disperse them into the solvent. "Our know-how is all about treating the surface of the particles with a surface-active agent so that it will adapt well to the solvent when dispersing, along with stabilizing the particle dispersion liquid," remarks Mr. Kimura. Transparent photo-catalytic film made in this way can be used to protect the lightings from dirty exhaust gas, or to make side-mirrors of cars fog-proof.

Another very promising material for Mr. Kimura is gold, particularly "gold nano-rods", which are gold bars 10nm in diameter and 50nm in length. They have a unique characteristic of selectively absorbing specific light, from visible to near-infrared. In particular, they can absorb 90% or more of infrared light that has a wavelength of 850nm.

For instance, infrared light radiated from a large TV plasma display has a wavelength of 800nm. Because this is the same wavelength as the infrared light used in a remote controller, the controller sometimes malfunctions. However, by applying gold nanorod coating on the display, this can be prevented.

"For semiconductor-related materials, we developed strained silicon wafers that exhibit high electron mobility," says Mr. Kimura.

To fabricate strained silicon wafers, an epitaxial layer of SiGe was first grown on a Si substrate, and then covered with a Si layer to give the strain. By combining this strained silicon wafer and nano-level CMP (chemical mechanical polishing) technology, the research group realized devices that boast electron mobility 2.2 times faster than that of conventional silicon transistors. This nano-level
deposition and polishing technology can also be applied to other products.

According to Mr. Kimura, "It is often said that those who succeeded in
developing prominent materials can rule the market. This shows how important materials are. We are trying from every angle to develop high-value-added and highly functional materials. Researchers' patience and effort are indispensable for achieving this goal." Along with developing highly functional materials, Mr. Kimura shows leadership in manufacturing technique, commercializing technique and marketing. This is because all these are needed to send his materials to the world. The road is not easy, but full of challenges. However, Mr. Kimura is optimistic, backed by his past results of overcoming difficulties and achieving success ….read the wave

... read the article


Hidekazu TANAKA,

Associate Professor, Atom Scale Science Division,
The Institute of Scientific and Industrial Research, Osaka

University, and Researcher, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency

Construction of strongly correlated electron devices by nanoscopic, functionally-harmonized artificial lattices


Transition metal oxides exhibit a rich variety of physical properties due to a strong correlation among electrons. The aim of this research is to construct novel, functional artificial materials and devices, which will enable us to control ferromagnetism, colossal magnetoresistance, superconductivity, or metal-insulator transition by light or electric field at room temperature.

We have combined these magnetic oxides with semiconductive oxides at a nanoscale in artificial lattices, and controlled the behavior of the correlated electrons through the interface.

We have been studying artificial superlattices such as colossal magnetoresistive superlattices, constructed by laser molecular beam epitaxy, and have observed that their physical properties changed drastically within 1 - 10 unit cell stacking periodicity.

When we fabricate p-n diode, field effect transistor and so on, at a nanoscale,
we can dynamically and drastically control the functionality of the transition metal oxides. This is the concept that forms the basis of "Strongly Correlated Electron Devices.

We have observed that the magnetic feature of lightly doped (La,Ba) MnO3 thin films have the potential to realize electric field control of ferromagnetism, demonstrating carrier-induced room temperature ferromagnetism, even in an ultrathin film with a 5 nm thickness. In field effect transistors, composed of ultrathin (La,Ba)MnO3 and
semiconductiveSr(Ti,Nb)O3 as a gate layer, we have successfully observed electric field control of metal-insulator transition above room temperature, suggesting that ferromagnetism at the interface is also modulated. We will investigate the spin state at the interface.

We believe that this research will open up a new discipline, "Strongly Correlated Electron Engineering," unifying "band gap engineering" and "Mott transition," which includes switching rich functionality such as ferromagnetism, superconductivity and so on. …read the wave

Shoichiro YOSHIDA

First stepper
Developing new technology based on what you master




An efficient single photon source using parametric down conversion





Inspiration from
outer space
Synthesizing artificial diamonds using shock pressure




Development of photoemission and
inverse-photoemission spectroscopy,
electronic structure of transition-metal compounds





Nanotube and nanohorn
Future real key player
of nanotechnology





Fabrication of novel core-shell nanostructured materials using the size-selective photoetching technique





Discovery of
multiple-decker sandwich clusters
" Opening up cluster chemistry




Xiaobing REN

Exotic multiscale phenomena associated with nano-order of point defects





Bridging the gap between technological
seeds and needs





Development of a bioactive-material consisting of an inorganic nanoparticle-organic-cell composite



Chris Phoenix

The Bugbear of Entropy




Fabrication of patterned film by self-organization -Utilization of the bottom-up approach
dependent on natural phenomena-



Surface structure determination
and development of
low-energy electron
diffraction for small
surface regions



Yoshio BANDO

Exploring new nanoscale materials
The world's smallest thermometer brought by serendipity and an inquisitive spirit



Design and application
of materials
with hierarchical
pore structure
via liquid phase


Kazunobu TANAKA

Four suggestions for developing nanotechnology as a key industry in Japan


Tadaaki NAGAO

Sheet plasmon and electron dynamics in
low-dimensional matter



Masayoshi ESASHI

Combining micromachining with nanomachining


Satoshi KAWATA

the diffraction limit
Photonics explores the nano world



Nanofabrication process for semiconductors
using atomic force microscope


Takaaki KOGA

Control and applications of novel spin properties found in semiconducting nano structures


Chris Phoenix

Science and Technology:
The Power of Molecular Manufacturing



Dr. Mae-Wan Ho

The Quantum Information



Yasunori TODA

Quantum mechanical control
of quantum dots by using coherently controlled light


Akihisa INOUE

"Metallic Glass"
opens a new field in
materials science

--Development of new
light weight,
high-strength materials-


Seigo Tarucha

Quest for quantum computing



Chihaya ADACHI

Organic electronics
and photonics



The New Nanotech Divide


Chris Phoenix

" Science and Technology:
Nucleic Acid Engineering "


" Creation of new functional materials utilizing nanotechnology "


Hidekazu TANAKA

Construction of strongly correlated electron devices by nanoscopic, functionally-harmonized artificial lattices "