Esaki, Leo (March 12, 1925 - ; Japan)

Leo Esaki, also known by his original name, Reiona Esaki, is a Japanese physicist specializing in solid-state physics as well as a researcher in superconductivity. In 1973, Esaki, along with Ivar Giaevar and Brian Josephson shared the Nobel Prize for Physics.

Born in Osaka, Esaki attended Tokyo University and graduated with his degree in physics in 1947 and with his Ph.D. in 1959. Upon his graduation from Tokyo University in 1947, Esaki took up a position with the Kobe Kogyo company. In 1956, Esaki accepted a position at the Sony Corporation and became its chief physicist working in the field of quantum mechanics. It was with this post that Esaki conducted his experiments which led to the Nobel Prize. While at Sony, Esaki concentrated on the concept of tunnelling in which electrons are able to pass through barriers once thought to be impenetrable. The electrons were noted to be able to move freely through the barrier due to the wavelength character of matter.

In 1960, Esaki moved to Yorktown, New York after being awarded the International Business Machines (IBM) fellowship to enable him to further his research in the United States. After obtaining the fellowship, Esaki joined IBM's research laboratories. Esaki is also noted as the inventor of the double diode which today bears his name-- the Esaki diode, by modifying solid-state semiconductors through the addition of impurities (Britannica, 4:553, 1994; and Barba, p.65, 1995).