Gregory Evgenievich (Ezekielevich) Pikus (May 7, 1923 – April 12, 1998) was a Soviet

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict natural phenomena. This is in contrast to experimental physics, which uses experi ...

whose contributions strongly influenced developing physics of

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

s. Among his most fundamental contributions are development of the method of invariants in band theory of solids, the Bir-Aronov-Pikus mechanism of spin relaxation of electrons, prediction of the circular photogalvanic effect, and theory of

weak localization Weak localization is a physical effect which occurs in disordered electronic systems at very low temperatures. The effect manifests itself as a ''positive'' correction to the resistivity of a metal or semiconductor. The name emphasizes the fact tha ...

in noncentrosymmetric structures. His three monographs E. L. Ivchenko and G. E. Pikus. Superlattices and other heterostructures: symmetry and optical phenomena (Springer, 2012), 2nd edition. reflect the focus points of the theory of semiconductors during the second half of the 20th century from transistors to band theory to properties to artificial nanostructures.

Life and career

Pikus was born in Moscow but afterwards the family moved to Minsk (currently Belorussia) where he graduated from high school. After the graduation, he became a student in the physical-engineering department of Leningrad (currently St. Petersburg) Polytechnic University in the fall of 1940. Two events overshadowed young years of his life. During the Great Terror of the late 1930s Pikus lost his family, and after the Nazi invasion of USSR in the summer 1941 Pikus volunteered to the Army which resulted in long break in his education. He fought from Leningrad to Austria and received high military honors for his service. In 1947 Pikus resumed his education in Leningrad Polytechnic University. After the graduation in 1951 he was directed for work at an electronic factory in Novosibirsk. During the ''Thaw'' that followed Stalin's death,

Abram Ioffe Abram Fedorovich Ioffe ( rus, Абра́м Фёдорович Ио́ффе, p=ɐˈbram ˈfʲɵdərəvʲɪtɕ ɪˈofɛ; – 14 October 1960) was a prominent Soviet Union, Soviet physicist. He received the USSR State Prize, Stalin Prize (1942), the ...

established in Leningrad the Institute for Semiconductors and Andrey I. Anselm, a head of the Theoretical Department of the institute, managed to bring his former student Pikus back to Leningrad. This allowed Pikus to start his research that lasted for four decades. He worked in the Institute for Semiconductors, and after its merging with the A. F. Ioffe Physical Technical Institute, in the Ioffe Institute to the rest of his life. Pikus contributed to various areas of physics of semiconductors from optical spectroscopy to charge and spin transport. Distinguishing features of his style were symmetry approach to theoretical problems and close connection to experimental work. Pikus's deep feeling on the role of symmetry developed during his work with Bir on the effect of

anisotropic Anisotropy () is the structural property of non-uniformity in different directions, as opposed to isotropy. An anisotropic object or pattern has properties that differ according to direction of measurement. For example, many materials exhibit ver ...

deformations on energy spectrum and physical propertied of semiconductors, a controversial subject at that time. In the future, this approach guided prediction of the photogalvanic effect, developing of a nondissipative electric current in homogeneous gyrotropic crystals under their illumination by circularly polarized light. It was first discovered in bulk Te crystals with a tricky band structure and more recently became a powerful tool in physics of

nanostructures A nanostructure is a structure of intermediate size between microscopic and molecular structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Ma ...

. Active experimental research on optical orientation in semiconductors performed in the Ioffe Institute attracted Pikus's attention and resulted in the Bir-Aronov-Pikus mechanism of spin relaxation and prediction of optical alignment of excitons. In the late period of his life, Pikus concentrated on developing a consistent theory of the weak localization corrections to magnetoconductivity of spin-orbit coupled media. Around Pikus grew a new generation of young theorists including such researchers as Gennady Bir,

Arkady Aronov Arkady Girshevich Aronov (, ; July 26, 1939 in Leningrad, Soviet Union – November 13, 1994 in Rehovot, Israel) was a Russian and Israeli theoretical condensed matter physicist, notable for his achievements in physics of semiconductors and in me ...

, and Eugene Ivchenko. Pikus was awarded the Ioffe Prize of the Academy of Sciences (1987),

USSR State Prize The USSR State Prize () was one of the Soviet Union’s highest civilian honours, awarded from its establishment in September 1966 until the dissolution of the USSR in 1991. It recognised outstanding contributions in the fields of science, mathem ...

(1988), and the Hanle Prize of the

Alexander von Humboldt Foundation The Alexander von Humboldt Foundation () is a foundation that promotes international academic cooperation between scientists and scholars from Germany and abroad. Established by the government of the Federal Republic of Germany, it is funded by t ...

(1993). The A. F. Ioffe Institute held in 2013 an all-Russia Seminar in commemoration of Pikus's 90th birthday.

References

External links

* * Symmetry and Physics. Preservation through Development, A seminar held in memory of 90th birthday of G. E. Pikus, http://www.ioffe.ru/symmetry/Pikus2013/Symmetry_and_Physics.html

Life and career

See also

References

External links

Further reading