was a Japanese

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

, best known for his development of

electron holography Electron holography is holography with electron waves. Dennis Gabor invented holography in 1948 when he tried to improve resolution in electron microscope. The first attempts to perform holography with electron waves were made by Haine and Mulvey ...

and his experimental verification of the

Aharonov–Bohm effect The Aharonov–Bohm effect, sometimes called the Ehrenberg–Siday–Aharonov–Bohm effect, is a quantum mechanical phenomenon in which an electrically charged particle is affected by an electromagnetic potential (φ, A), despite being confine ...

Biography

Tonomura was born in Hyōgo, Japan, and graduated from

the University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...

with a degree in physics. Upon graduation he joined the

Hitachi () is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...

Central Research Laboratory, where he later attained the title "Fellow" in 1999. In the 1970s, Tonomura did pioneering work in the development of the

microscope and observed lines of magnetic force for the first time in the world. Building on this, in 1986, he experimentally verified the

, which had eluded definitive experimental proof for a long time. This experiment proved that

vector potential In vector calculus, a vector potential is a vector field whose curl is a given vector field. This is analogous to a ''scalar potential'', which is a scalar field whose gradient is a given vector field. Formally, given a vector field v, a ''vecto ...

s, which are nothing more than a mathematical concept in

classical physics Classical physics is a group of physics theories that predate modern, more complete, or more widely applicable theories. If a currently accepted theory is considered to be modern, and its introduction represented a major paradigm shift, then the ...

, are in fact physical quantities that are more fundamental than electric or magnetic fields. Tonomura was also known for his observations of magnetic vortex movement in superconductors.

List of books available in English

* ''Electron Holography, 2nd edition''/A. Tonomura, Springer, Springer Series in Optical Sciences (1999)

References

External links

Hitachi Fellow: Dr. TONOMURA Akira
{{DEFAULTSORT:Tonomura, Akira 1942 births 2012 deaths People from Nishinomiya Japanese physicists University of Tokyo alumni Foreign associates of the National Academy of Sciences Riken personnel Fellows of the American Physical Society