The Franklin Institute, located in Philadelphia, has announced that it is awarding the 1999 Benjamin Franklin Medal of The Franklin Institute in Physics to Dr. Akira Tonomura, Senior Chief Research Scientist of the Advanced Research Laboratory of Hitachi, Ltd.
Dr. Tonomura is receiving the award for his work on
the development of the holography electron microscope1, which uses a high-brightness field-emission electron beam,
and for his verification of the Aharonov-Bohm effect2
and observations of the dynamic behavior of magnetic vortices in superconductor3, using the holography electron microscope.
The award ceremony will take place on April 29, 1999, at The Franklin Institute, which will also host an international symposium to commemorate the occasion.
The Franklin Institute presents the Bower Award in
two categories, science and management, and the Benjamin Franklin Medal is awarded in the five categories
of physics, chemistry, life science, engineering and computer and cognitive science. Dr. Tonomura's award
is in the physics category. Recipients over the 174-year history of award include such famous names as the inventors, Thomas Edison and the Wright brothers,
and the physicists Marie Curie, J. J. Thomson,
Albert Einstein, Wolfgang Pauli, indicating the highly prestigious status the award has among the world's physics prizes. There have been two previous Japanese recipients: Dr. Leo Esaki in 1961, and Dr. Akito Arima, in 1990. Some 15% of Nobel Prize-winners in physics first received the Benjamin Franklin Medal.
The Franklin Institute is a non-profit foundation established in Philadelphia in 1824 to commemorate Benjamin Franklin. The Institute promotes science and technology, and is also known for its famous science museum.
Notes:
1. Development of the high-brightness, field-emission holography electron microscope
According to quantum theory, electrons can have both wave and particle characteristics. Thus, passing electrons through a sample gives rise to interference fringes that can be used to observe the behavior of electric and magnetic fields in the sample. The use of a high-brightness beam of field-emission electrons made it possible for the first time to observe thousands of interference fringes, and made the holography electron microscope a practical instrument.
2. Verification of the Aharonov-Bohm effect
In electromagnetics it has long been convenient to
use a quantity known as the vector potential when calculating electric and magnetic fields. In a
1959 paper Aharonov and Bohm advanced the theory
that the vector potential was not just a mathematical convenience but actually existed. This led to a number of attempts to provide experimental verification of
the Aharonov-Bohm effect. All of these fell short of the goal, so the debate continued unabated until 1986. In that year, Dr. Tonomura and his colleagues conclusively verified the existence of the effect, using
the holography electron microscope and sample
fabricated using microlithographic techniques and
maintained in a superconducting state. This
also provided empirical underpinning for gauge theory.
3. Observation of the dynamic behavior of magnetic vortices in superconducting materials
Magnetic vortices in superconducting materials play
a major role with respect to the practical application
of superconductors. Formally, however, it was impossible to observe the dynamic behavior of vortices. Video recording of the dynamic behavior of vortices was
first achieved with Lorenz microscopy using the holography electron microscope.
WRITTEN
BY Secretary's Office
All Rights Reserved, Copyright
(C) 1998, Hitachi, Ltd.
