John Bardeen (born 23.05.1908) is an American physicist and a member of the National Academy of Sciences (1954). He was born in Madison. He graduated from the University of Wisconsin (1928) and from Princeton University. In 1935-38 he worked at Harvard University, in 1938—41 at the University of Minnesota and in 1945—51 at the Bell Telephone Laboratories; since 1951 he has been professor at the University of Illinois. His research concerned solid-state physics and superconductivity. Together with W. Brattain he discovered the transistor effect in 1948 and created the point-contact crystal triode, the first semiconductor transistor (the Nobel Prize, 1956). Together with G. Pearson he studied a large number of samples of silicon with various contents of phosphorus and sulfur and examined the mechanism of scattering by donors and acceptors (1949). In 1950, with W. Shockley, he introduced the concept of the deformation potential. Independently of H. Fröhlich he predicted (1950) an attraction between electrons arising from the exchange of virtual phonons; in 1951 he attempted to construct a theory of superconductivity based on taking the electron-phonon interaction into account, and in 1952 he calculated the attraction between electrons due to the exchange of virtual phonons. In 1957, together with L. Cooper and J. Schrieffer, he constructed the microscopic theory of superconductivity (the Bardeen—Cooper—Schrieffer theory) (the Nobel Prize, 1972). He developed the theory of the Meissner effect on the basis of a model with an energy gap, and independently of others he generalised in 1958 the theory of the electromagnetic properties of superconductors to the case of fields of arbitrary frequency. In 1961 he proposed the effective-Hamiltonian method in the theory of tunnelling (the Bardeen tunnelling model), and in 1962 he calculated the critical fields and currents for thin films.
In 1968—69 he was president of the American Physical Society. The F. London Medal (1962), the National Medal of Science (1965) and others.