Yakov Frenkel


Yakov Il'ich Frenkel was a Soviet physicist renowned for his works in the field of condensed matter physics. He is also known as Jacov Frenkel, and he frequently put down his name as J. Frenkel when he published his papers in journals in English.

Early years

He was born in a Jewish family in Rostov on Don, in the Don Host Oblast of the Russian Empire on 10 February 1894. His father was involved in revolutionary activities and spent some time in an internal exile to Siberia; after the danger of pogroms started looming in 1905, the family spent some time in Switzerland, where Yakov Frenkel began his education. In 1912, while studying in the Karl May Gymnasium in St. Petersburg, he finished his first work in physics on the earth's magnetic field and atmospheric electricity. This work attracted Abram Ioffe's attention and later turned into collaboration. He considered moving to the USA but was nevertheless admitted to St. Petersburg University in the winter semester of 1913, at which point any emigration plans perished. Frenkel graduated from the university in 3 years and remained there to prepare for a professorship. His first scientific paper came to light in 1917.

Beginning of scientific career

In the last years of the Great War and until 1921 Frenkel was involved in the foundation of the University in Crimea. From 1921 till the end of his life, Frenkel worked at the Physico-Technical Institute. Beginning in 1922, Frenkel published a book virtually every year. In 1924 he published 16 papers, three books and edited multiple translations. He was the author of the first theoretical course in the Soviet Union. Many students learned physics from these books, in the Soviet Union and abroad. For his distinguished scientific service, he was elected a corresponding member of the USSR Academy of Sciences in 1929.
He married Sara Isakovna Gordin in 1920. They had two sons, Sergei and Viktor. He served as a visiting professor at the University of Minnesota in the United States for a short period of time in around 1930.
Early works of Yakov Frenkel were in the field of electrodynamics, statistical mechanics and relativity, though he soon switched to the quantum theory. Paul Ehrenfest, whom he met at a conference in Leningrad, encouraged him to go abroad for collaborations which he did in 1925–1926, mainly in Hamburg and Göttingen, and met with Albert Einstein in Berlin. It was during this period when Schrödinger published his groundbeaking papers on wave mechanics; Heisenberg's appeared shortly before. Frenkel enthusiastically entered the field by discussions but his first scientific paper on the matter was published in 1927.
In 1927–1930 he discovered the reason for the existence of domains in ferromagnetics; worked on the theory of resonance broadening and collision broadening of the spectral lines; developed a theory of electric resistance on the boundary of two metals on of a metal and a semiconductor.

The time of the most famous discoveries

When conducting research on the molecular theory of condensed state, he introduced the notion of the hole. The Frenkel defect became firmly fixed in the physics of solids and liquids. In the 1930s, his research was supplemented with works on the theory of plastic deformation. His theory, now known as the Frenkel–Kontorova model, is important in the study of dislocations. Tatyana Kontorova was then a PhD candidate working with Frenkel.
In 1930 to 1931, Frenkel showed that neutral excitation of a crystal by light is possible, with an electron remaining bound to a hole created at a lattice site identified as a quasiparticle, the exciton. Mention should be made of Frenkel's works on the theory of metals, nuclear physics, and semiconductors.
In 1930 his son Viktor Frenkel was born. Viktor became a prominent historian of science, writing a number of biographies of prominent physicists including an enlarged version of Yakov Ilich Frenkel published in 1996.
In 1934, Frenkel outlined the formalism for the multi-configuration self-consistent field method, later rediscovered and developed by Douglas Hartree.
He contributed to semiconductor and insulator physics by proposing a theory, which is now commonly known as the Poole–Frenkel effect, in 1938. "Poole" refers to H. H. Poole, Ireland. Poole reported experimental results on the conduction in insulators and found an empirical relationship between conductivity and electrical field. Frenkel later developed a microscopic model, similar to the Schottky effect, to explain Poole's results more accurately. In this paper published in USA, Frenkel only very briefly mentioned an empirical relationship as Poole's law. Frenkel cited Poole's paper when he wrote a longer article in a Soviet journal.
During the 1930s, Frenkel and Ioffe opposed dangerous tendencies in Soviet physics, binding science and materialist ideology, which shows their remarkable courage. Soviet physics as a result of these actions never spun down as much as biology. Still, he afterwards forwent publishing several papers, fearing it will lead to some unfortunate consequences.
Yakov Frenkel was involved in the studies of liquid phase, too, – since mid 1930s and during the World War II, when the institute was evacuated to Kazan. The results of his more than twenty years of study of the theory of liquid state were generalized in the classic monograph "Kinetic theory of liquids".

Later years

During the wartime, he worked on contemporary practical problems to help his country in sustaining the harsh war. After the war Frenkel was interested in seismoelectrics, also proposing that sound waves in metals might cause some electric phenomena. He subsequently worked mainly in the field of atmospheric effects, but did not abandon his other interests, publishing several papers in nuclear physics.
Frenkel died in Leningrad in 1952. His son, Victor Frenkel, wrote a biography of his father, Yakov Ilich Frenkel: His work, life and letters. This book, originally written in Russian, has also been translated and published in English.

English translations of books by Frenkel

Literature