James Charles Phillips (born March 9, 1933) is an American physicist and a member of the National Academy of Science (1978). Phillips invented the exact theory of the ionicity of chemical bonding in semiconductors, as well as new theories of compacted networks (including glasses, high temperature superconductors, and proteins).
Phillips was born in New Orleans and grew up in several Western states (Arizona, Colorado and New Mexico). After graduating from Albuquerque HS in 1950, he went to the University of Chicago, where he received M.S. in both mathematics and physics. He was the grader in Enrico Fermi’s last course (1955). He studied with Morrel H. Cohen, with a Ph.D. thesis on algebraic topology (1956). He joined the Theoretical Physics group at Bell Laboratories, newly formed and under the leadership of Conyers Herring (1956-1958). Following a suggestion by Herring, Phillips invented a simplified (PseudoPotential, PP) theory of the electronic structure of semiconductors, and produced the first electronic structures of Silicon and Germanium semiconductors in good agreement with known properties (1958).
Phillips spent postdoctoral years at Univ. California (Berkeley) with Charles Kittel, and at the Cavendish Lab., Cambridge Univ., where he introduced PP ideas that were used there for decades by Volker Heine and others. He returned to the University of Chicago as a faculty member (1960-1968). There he and Marvin L. Cohen extended PP theory to calculate the fundamental optical and photoemission spectra of many semiconductors, with high precision. Highly accurate PP placed the electronic structure of semiconductors almost on a par with that of atoms (Niels Bohr, the planetary model, 1913). PP culminated in his “exact” dielectric ionicity theory (1968), which still is the only theory to improve on the previously best ionicity theory of Linus Pauling. During his time at Chicago, Phillips also co-authored (with Morrel Cohen and Leo Falicov) the microscopic theory of superconductive tunneling (1962), replacing a (1961) theory by John Bardeen. The “CFP” theory was the basis of Brian Josephson’s theory of his Effect (1962).