Solomon Isaakowitsch Pekar

Solomon Isaakowitsch Pekar ( Russian Соломон Исаакович Пекар , Ukrainian Соломон Ісакович Пекар / Solomon Pekar ; born March 16, ^jul. / 29 March  1917 ^greg. In Kiev , Russian Empire , † 8. July 1985 in Kiev, Ukrainian Soviet Socialist Republic ) was a Ukrainian theoretical physicist , solid state physicist and university lecturer .

Life

Pekar was born into a Jewish family. He studied physics at Kiev University . In 1941 he received his doctorate in physical-mathematical sciences . In 1944 he was appointed professor as head of department. After the German-Soviet War , Pekar was appointed to the new chair for theoretical physics at the University of Kiev.

In 1946, Pekar developed the Polaron concept to describe the electrostatic bond between an electron and a polar optical phonon . In the case of the strong bond, he determined the binding energy of the polaron, the effective mass of which is described by the Landau-Pekar equation . Pekar's model became a field theory without singularities , which was then also applied to medium and weak electron-phonon bonds.

Generalizations concerned the binding of electrons to acoustic phonons and magnons , to excitonic polarons, polarons in low-dimensional systems and bipolarons. Methods of polaron theory have been applied to the theory of the optical spectra of pollution centers, with the intensity distribution of the Phonon satellites known as the Pekar distribution . The polaron and bipolaron concept found its way into the theory of superconductivity, especially for describing the phase transitions between BCS phases and Bose-Einstein phases .

1957 by Pekar a theory of electromagnetic waves near exciton - resonances , as now polaritons are known. He predicted additional new waves of light ( pekar waves ) that would arise due to the small effective mass of the electronic excitons. These waves were then observed experimentally and registered as a discovery. Pekar's theory predicted the violation of the Kramers-Kronig relationships in polariton resonances, which was confirmed experimentally.

In 1960, together with WE Laschkarjow , Pekar founded the Institute for Semiconductor Physics of the Academy of Sciences of the Ukrainian Soviet Socialist Republic (AN-USSR) (later WE Laschkarjow Institute for Semiconductor Physics ) in Kiev. In 1961, Petar became a member of the AN-USSR.

Pekar's students included MA Kriwoglas , JE Perlin , KB Tolpygo , IM Dykman and EI Raschba .

The AN-USSR donated the Pekar Prize for Theoretical Physics .

Honors

• State Prize of the USSR (1981)
• State Prize of the USSR

Individual evidence

1. ↑ JA Chramow: Pekar Solomon Isaakowitsch . In: AI Achijeser : Physicists: Biographical Lexicon . Nauka, Moscow 1983, p. 210 (Russian).
2. ↑ Russian Jewish Encyclopedia: Pekar Solomon Isaakowitsch . (Russian) Retrieved May 21, 2016.
3. ↑ In memory of Solomon Isaakowitsch Pekar . (PDF; Russian) Retrieved May 21, 2016.
4. ↑ LD Landau, SI Pekar: Effective mass of a polaron . In: Ukr. J. Phys., Special Issue . tape 53 , 2008, p. 71–74 ( ujp.bitp.kiev.ua [PDF; accessed on May 21, 2016]). ujp.bitp.kiev.ua ( Memento of the original from March 5, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
5. ↑ JJ Markham. In: Rev. Mod. Phys. , 31 (1959), p. 956.
6. ↑ Polarons . In: AS Alexandrov (ed.): Advanced Materials . Canopus, Bristol UK 2007.
7. ↑ MV Lebedev, VB Timofeev, MI Strashnikova, VV Chernyi: Direct observation of two polariton waves near the main exciton resonance in CdS crystals . In: JETP Letters . tape 39 , 1984, pp. 440–444 ( jetpletters.ac.ru [PDF; accessed May 21, 2016]).
8. ^ SI Pekar, Certificate No. 323, OT-11003 (September 27, 1984); Otkrytiya, Izobret., No. 32, 3 (1987) (Russian).
9. ↑ SL Robinette, GJ Small. In: J. Chem. Phys. , 65 (1976), p. 837.