Japanese physicist Akira Tonomura, a fellow at electronics giant Hitachi Ltd. tipped for years as a Nobel Prize contender, died of pancreatic cancer early Wednesday at a hospital in Hidaka, Saitama Prefecture, sources said. He was 70.
Tonomura is known for developing electron holography for observing microscopic structures of matter using the wave nature of electrons and confirming the so-called Aharonov-Bohm effect, whose existence had long been disputed among physicists.
A native of Hyogo Prefecture, Tonomura joined Hitachi in 1965 after graduating from the University of Tokyo and soon began engaging in the development of the electron microscope at a laboratory of the company.
His confirmation of the Aharonov-Bohm effect, in which electrons are physically affected when passing through a space free from magnetic fields, through experiments during the 1980s elevated him to the ranks of physicists viewed as candidates for the Nobel Prize.
Selected as a person of cultural merit, Tonomura was given the Nishina Memorial Prize, the Japan Academy Prize and the U.S. Benjamin Franklin Medal, among other awards.