US physicist, whose invention of the point-contact transistor and the theory to explain superconductivity won him two Nobel Prizes, the first physicist to do so.
Born in Madison, Wisconsin, the son of an anatomy professor, Bardeen studied electrical engineering at the University of Wisconsin. After working for three years as a geophysicist he entered Princeton as a graduate student, gaining his PhD in mathematical physics in 1936. Bardeen subsequently held brief appointments at Harvard and the University of Minnesota, before joining the Naval Ordnance Laboratory in World War II. In 1945 Bardeen joined the Bell Telephone Laboratories, where a new group had been formed to work on the development of solid-state devices. Here, in collaboration with W. H. Brattain, Bardeen published a paper introducing the transistor (1948). For this discovery, which changed the whole electronics industry, and indeed many aspects of society, Bardeen won the first of his Nobel Prizes (1956) in conjunction with Brattain and W. B. Shockley.
In 1951 Bardeen moved to the University of Illinois as professor of physics and electrical engineering. Here, with his colleagues L. N. Cooper (1930– ) and J. R. Schrieffer(1931– ), he tackled the problem of superconductivity. Although the phenomenon was first described by K. Onnes in 1911, no theoretical explanation had been accepted for it. The crucial insight of the BCS (Bardeen–Cooper–Schrieffer) theory is that at very low temperatures, under certain conditions, electrons can form bound pairs (Cooper pairs). For his work on superconductivity Bardeen was awarded his second Nobel Prize for Physics (1972), sharing it with Cooper and Schrieffer.
Subjects: Science and Mathematics — History.