Esaki, << ehs ah kee, >> Leo (1925-…), is a Japanese solid-state physicist, specializing in superconductivity and a phenomenon known as electron tunneling (see Superconductivity ). Esaki shared the 1973 Nobel Prize for physics with Ivar Giaever of the United States and Brian Josephson of the United Kingdom for their work on electron tunneling through semiconductor and superconductor materials.
Electron tunneling explains how electrons can, under certain circumstances, penetrate seemingly uncrossable materials. This penetration occurs because matter can sometimes behave like waves. Scientists make use of the property of tunneling in an instrument known as the scanning tunneling microscope (see Scanning probe microscope ). Esaki invented the double diode, the first quantum electron device.
In 1960, Esaki began researching into semiconductors (substances with an electrical conductivity between that of metals and insulators). See Semiconductor . Esaki’s invention, the tunnel diode, allows electrons to “tunnel” across a junction despite not having enough energy to cross the barrier.
Leo Esaki was born in Osaka, Japan. He studied at the University of Tokyo, receiving a Ph.D. in 1959. He worked for the Sony Corporation from 1956 to 1960 and for International Business Machines Corporation (IBM) in Japan from 1960 to 1992, serving as director of IBM-Japan from 1976 to 1992. He became president of the University of Tsukuba in Japan in 1992.
