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JAPAN NANONET BULLETIN
-- 9th Issue -- January 8, 2004
Nanotechnology Researchers Network Center of Japan
Ministry of Education, Culture, Sports, Science and Technology (MEXT)
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IN THIS ISSUE
Nanonet Interview:
Akira TONOMURA, Fellow, Hitachi Ltd. and Group Director, The
Institute of Physical and Chemical Research (Riken)
Young Researchers’ Introduction:
Isamu MORIGUCHI, Associate Professor, Department of Applied
Chemistry, Faculty of Engineering, Nagasaki University and Researcher,
Precursory Research for Embryonic Science and Technology (PRESTO),
Japan Science and Technology Agency (JST)
What’s in the next issue?
-- NANO CALENDAR --
For information on nanotechnology related symposiums and conferences
held in the world,
http://www.nanonet.go.jp/english/calendar/
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NANONET INTERVIEW
Going beyond quantum mechanics
-- the challenge of holography electron microscopy --
(Issued in Japanese: March 11, 2003)
Akira TONOMURA, Fellow, Hitachi Ltd. and Group Director, The
Institute of Physical and Chemical Research (Riken)
What is “the most beautiful experiment in physics”? When British
magazine Physics World asked this question, its readers chose the
double-slit experiments with single electrons, Dr. Tonomura and others
carried out. “Following our experiments, you could see big names like
Galileo and Newton in the top five,” Dr. Tonomura says with a smile.
Richard Feynman once called the double-slit experiments “the heart of
quantum mechanics but impossible to perform.” Dr. Tonomura succeeded
in carrying out the experiment to show, for the first time, the
essence of quantum mechanics--that single electrons can have
characteristics of both waves and particle.
“I had always admired the ripples of water since I was a child. And
when I went to university and studied quantum mechanics, I was taught
that electrons are also waves. This motivated me to want to see the
ripples of electrons with my own eyes, and made me decide to go into
this area.” In 1968, Dr. Tonomura developed the holography electron
microscope and continued to increase the brightness of electrons.
Since then, he has led the world in research utilizing holography
electron microscopy. In 1978, he succeeded in observing the magnetic
lines of force. In 1982, he conclusively verified the existence of the
Aharonov-Bohm effect, and demonstrated that vector potential actually
exists. Until then, vector potential had been regarded as a quantity
used for mathematical convenience, without any physical meaning.
However, Dr. Tonomura verified that the vector potential is a more
fundamental physical entity that also affects electrons than electric
or magnetic fields.
Furthermore, in 1989, he achieved the first dynamic observation of the
magnetic flux quanta inside superconductors; sometimes it was a river-
like motion. In order to keep the superconductive state, it is
necessary to pin down the magnetic flux quanta. It was known
empirically that this could be done where there were defects in the
superconductor. By his dynamic observation, Dr. Tonomura succeeded in
catching the figure for the first time. “Direct observation of
magnetic flux quanta had long been a dream for specialists in electron
microscopy like myself, but at last we succeeded in doing this.
Technical development and research are inseparable, like a pair of
wheels of a carriage. If you can obtain the best technology, it would
become possible to do research on what was seen as impossible before.”
In the year 2000, Dr. Tonomura succeeded in developing a 1 million-
volt holography electron microscope with the world’s highest
resolution and beam brightness. The line-resolution was better than 0.
5 A (angstrom), with a brightness level of 2x10^10 (A/cm^2 sr), which
was 4 digits higher than that of the electron beam used in his initial
microscope.
Having obtained the world’s best technology, Dr. Tonomura is now using
it to observe magnetic flux quanta in a “high-temperature”
superconductor. Because the superconductor has a layered structure,
the behavior of magnetic flux quanta becomes much more complicated
than in conventional metallic superconductors. One of the unique
phenomena observed in high-temperature superconductors is the chain of
magnetic flux quanta. When a magnetic field is applied perpendicular
to the layer plane of a high-temperature superconductor, the magnetic
flux quanta form a closely-packed triangular lattice. However, with a
tilted magnetic field, a tight array or "chain" of magnetic flux
quanta is formed within the magnetic flux quanta forming the
triangular lattice. It has been guessed that the flux quanta run
obliquely, inside the superconductors, but Dr. Tonomura revealed in
his research that Josephson quanta penetrate between the layers, and
magnetic flux quanta perpendicularly crossing them form the chains.
These results are considered to include the keys to clarifying the
mysteries of high-temperature superconductors.
“I regard myself as a specialist on photography using the electron
microscopy. Photographs include a variety of information. Beauty of
the image as well as theory is an important element in judging whether
the information shown on a photograph is true or not. With our effort,
we would be able to obtain beautiful images that would allow us to see
new things. This is what attracts me so much to pursue the nano-order
world.” Dr. Tonomura’s curiosity seems to be endless. But it all
started from his admiration of water ripples. Dr. Tonomura expects
young people to have the same feeling he does. “I want them to first
of all find out what they like to do. It is much easier to persuade
others if you try to start research that is already an area of
interest by everybody else. But you won’t be able to surprise people
that way. On the contrary, if you try to go into an unconventional
field of research, you need to persuade people first, which would
require a lot of effort. But if that is what you want to do, it
shouldn’t be too painful.” This is the road that Dr. Tonomura himself
has been following.
Dr. Tonomura did not forget to add that researchers alone cannot bring
development to science and technology. “It is necessary for the people
to pay respect to those that have achieved outstanding results. When
Rikidozan, the star professional wrestler in Japan back in the 1950‚s,
was fighting a match, every single person in the nation was watching
him on the TV. If we can grow an amazing person like that in the world
of science, the entire nation will turn their eyes to science. If
everybody‚s watching, researchers will be able to do a much better job.
People‚s attention and researchers‚ efforts are both necessary for the
development of science and technology.” One of the projects that Dr.
Tonomura is paying attention to at the moment is the Super-Kamiokande
project. Just like Dr. Tonomura himself, the project is aimed at
pursuing the truth of the unseen. Even when succeeding in making an
invisible thing visible, there is always the next unseen object to
confront. Dr. Tonomura says, “As a matter of fact, I sometimes feel
that observation of living organisms may also be interesting. But
there are still so many compelling phenomena in the world of physics."
"If we continue with our observations using electron microscopy, we
may come against a phenomenon that cannot be explained with quantum
mechanics. Quantum mechanics has always been successful since it was
founded, but this doesn‚t mean it will keep on being successful in the
future. We humans haven‚t revealed everything.” Quantum mechanics came
after classical mechanics. What then will come after quantum
mechanics? “In order to find that out, we need to have some research
to start off with. Who knows? It may be research on nanotechnology
that will trigger the finding.”
(Interviewer: Kuniko Ishiguro)
For more information,
http://www.nanonet.go.jp/english/mailmag/2004/009a.html
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YOUNG RESEARCHERS’ INTRODUCTION
Soft chemical synthesis of functional inorganic nanostructured
materials
(Issued in Japanese: March 11, 2003)
Isamu MORIGUCHI, Associate Professor, Department of Applied
Chemistry, Faculty of Engineering, Nagasaki University and
Researcher, Precursory Research for Embryonic Science and
Technology (PRESTO), Japan Science and Technology Agency (JST)
Of late, the soft chemical process for the synthesis of inorganic
materials has attracted considerable attention, especially with regard
to its application in green material science & technology, processing
of new materials, and nanotechnology. The present work is an
interdisciplinary study of colloid and surface chemistry, molecular
assembly chemistry and ceramic chemistry, which aims at designing and
fabricating organic-inorganic nanocomposites and inorganic
nanostructured materials which would, in turn, lead to the development
of novel functional materials.
To date, we have been studying the soft chemical synthesis of thin
films and porous materials with the assistance of molecular and
colloidal assembly systems. As an example, ultrathin and hetero-
layered films of metal oxides were successfully synthesized using a
two-dimensional sol-gel process, in which the sol-gel reaction was
carried out at an air/water interface and the obtained floating gel
film was transferred onto substrate by Langmuir-Blodgett (LB)
technique. Porous materials have also been subjected to soft chemical
synthesis using micelle, middle phase microemulsion, and polystylene
latex (opal) crystals as templates.
In addition to the above syntheses, we are now investigating the
correlation between nanostructures and their photo- and electro-
chemical properties in order to develop novel nanodevices.
For more information,
http://www.nanonet.go.jp/english/mailmag/2004/009b.html
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WHAT’S IN THE NEXT ISSUE?
Nanonet Interview:
Motoichi OHTSU, Professor, Interdisciplinary Graduate School of
Science and Engineering, Tokyo Institute of Technology
Young Researchers’ Introduction:
Tetsu YONEZAWA, Department of Chemistry, School of Science, The
University of Tokyo and Researcher, Precursory Research for Embryonic
Science and Technology (PRESTO), Japan Science and Technology
Corporation (JST)
The next issue of JAPAN NANONET BULLETIN will be delivered on January
22, 2004.
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Nanotechnology Researchers Network Center of Japan distributes
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Nanotechnology Researchers Network Center of Japan
Ministry of Education, Culture, Sports, Science and Technology (MEXT)
Our website: http://www.nanonet.go.jp/english/
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