Yakov I. FRENKEL Ioffe Institute Home Page
Yakov I. FRENKEL, photo Yakov Il'ich Frenkel was born on February, 10, 1894, in Rostov on Don. He entered St. Petersburg University in 1910. Frenkel graduated from the University in 3 years and remained there to prepare for a professorship. In 1912 he finished his first work in physics on the earth magnetism and atmospheric electricity. This work attracted A. F. Ioffe's attention and later turned into collaboration.

From 1921 till the end of his life, Frenkel worked at the Physico-Technical Institute. When conducting research on the molecular theory of condensed state, he introduced the notion of the hole, and the "Frenkel defect" was firmly fixed in the physics of solids and liquids. In the thirties, his research was supplemented with works on the theory of plastic deformation. For his distinguished scientific services, he was elected a corresponding member of the USSR Academy of Sciences in 1929.

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". In 1930-1931, 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 quasi-particle—the exciton. Mention should be made of Frenkel's works on the theory of metals, nuclear physics (the liquid drop model of the nucleus), semiconductors. Frenkel's book-writing activity was extremely high. Beginning in 1922, he published a book virtually every year: he was the author of the first theoretical course in the USSR. Many students learned physics from these books, not only here but also in foreign countries.