Leonid Weniaminowitsch Keldysch

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Leonid Weniaminowitsch Keldysch ( Russian Леонид Вениаминович Келдыш , English transcription Leonid Veniaminovich Keldysh and often quoted from LV Keldysh; * April 7, 1931 in Moscow ; † November 11, 2016 there ) was a Russian physicist.

Life

Leonid Weniaminowitsch Keldysh, the son of Lyudmila Vsevolodovna Keldysh and stepson of Pyotr Sergejewitsch Novikow , graduated from Lomonosov University in 1954 , where he became a professor in 1965. He was at the Lebedev Institute , where he completed his habilitation in 1965 on non-equilibrium phenomena (Russian doctorate). That was actually his dissertation; Due to its high quality, it was also accepted as a habilitation. From 1968 he was a member of the management committee and from 1989 to 1994 was director (at the same time as head of the theoretical department). At the Lebedev Institute he was initially a student of Vitali Lasarewitsch Ginsburg and in the department of Igor Tamm . From 2004 to 2011 he was a part-time professor at Texas A&M University . In 1997 he was an X-ray guest professor at the University of Würzburg .

In 1968 he became a corresponding member of the Soviet Academy of Sciences and he has been an external member of the National Academy of Sciences since 1995 . In 1974 he received the Lenin Prize , in 1975 the Hewlett-Packard Prize of the European Physical Society and in 1994 the Humboldt Research Prize . In 2005 he received the S. I. Wawilow gold medal . In 2011 he was awarded the Eugene Feenberg Memorial Medal , in 2014 the Pomeranchuk Prize and in 2015 the Lomonosov Gold Medal .

He mainly dealt with solid state physics. Here he is known for the application of the quantum field theoretical formalism to non-equilibrium phenomena (development of a diagram technique around 1964), with applications, for example, to solid-state interactions of lasers, and the Franz Keldysh effect (1957/58), which is the basis for an important spectroscopic technique for determining the band structure of semiconductors was used. He described a variety of nonlinear optical effects in semiconductors in high external electric fields, which are associated with collective effects in electron-hole quantum liquids of high density. He developed a theory of electron-hole liquids and in 1968, together with his PhD student Alexander Kozlov, predicted the existence of drops of such electron-hole liquids in semiconductors (and thus a new phase of matter) and the existence of Bose-Einstein condensation of excitons. He dealt with exciton and bi-exciton systems and their instabilities and dealt with non-stationary collective effects in electron-hole systems. He also predicted superlattices in semiconductors (1962) and phonon-assisted electron tunneling (in his work on the Franz Keldysh effect), both of which also became active research directions (phonon-assisted tunneling in particular in the Esaki diode , superlattices in heterostructures were picked up in 1970 by Leo Esaki and Raphael Tsu and formed the basis of many optoelectronic devices).

In 1965 he introduced the concept of the excitonic insulator (with applications to various metal-semiconductor junctions) with his PhD student Yuri Kopaev, and he predicted the phenomenon of phonon wind, which was also confirmed experimentally.

From 2009 to 2016 he was the editor of Uspechi fisitscheskich nauk ( Успехи физических наук ). From 1991 to 1996 he headed the General Physics Department of the Russian Academy of Sciences.

Web links

Individual evidence

  1. ↑ Biographical data from American Men and Women of Science , Thomson Gale 2005
  2. ↑ LV Keldysh, Diagram technique for nonequilibrium processes , Sov. Phys. JETP 20 , 1018 (1965)
  3. ^ Indication of the research areas at the Tamm Institute
personal data
SURNAME Keldysch, Leonid Weniaminowitsch
ALTERNATIVE NAMES Келдыш, Леонид Вениаминович (Russian spelling)
BRIEF DESCRIPTION Russian physicist
DATE OF BIRTH April 7, 1931
PLACE OF BIRTH Moscow
DATE OF DEATH November 11, 2016
Place of death Moscow