Image of James M. Knight

James M. Knight

Distinguished Professor

Room 402E
Physics and Astronomy
University of South Carolina
Columbia, South Carolina 29208
(803) 777-6046

Research Interests

Theoretical Physics, Condensed Matter Physics. Physics is a field in which the fundamental laws are few in number and broad in scope. At the frontier, physicists are continually striving to find more encompassing viewpoints and unifying principles. Once discovered and formulated, these principles can be applied to an astonishingly diverse range of phenomena of interest and importance. Working in theoretical physics, not tied to specific experimental equipment, has led me to work, at lest briefly, on fields as diverse as quantum field theory, quantum optics, chaotic dynamics, and galactic astronomy. Recently, my work has been in close association with experimental physics investigating areas of condensed matter physics. Although the basic laws governing the behavior of crystalline solids, liquids, and amorphous material have been known for more than a half century, a rich variety of new phenomena continues to occupy the attention of workers in this field, partly due to advances in experimental techniques and partly due to increased theoretical insight. Some of these discoveries have the potential for important practical application, but the focus for physicists is always on understanding the "new physics" involved. In order to give an idea of the areas my work deals with, let me cite some of the problems currently occupying my attention in the fields of superconductivity and of ferroelectric materials. We are attempting to understand aspects of the process by which ferroelectric crystals form separate spatial regions, or domains, in which electric charges are displaced in opposite directions, and the conditions that determine how these regions are altered in the presence of electric fields. Another problem being investigated is the possibility that crystals of a particular family of ferroelectrics could undergo a spontaneous regular distortion incommensurate with the spacing of the atoms in the crystal. In the field of superconductivity we are trying to understand the mechanism of absorption energy by high temperature superconductors from high frequency electromagnetic fields and to account for some specific experimental results in this area. Another investigation in progress is the exploration of alternative mechanisms that might lead to superconductivity in layered structures.

Selected Publications

  • "Weak Measurement of Photon Polarization," with Lev Vaidman, Physics Letters, A143, 357 (1990).
  • "Evidence for an Incommensurate Phase in KH2PO4from ESR Measurements," with H. A. Farach, M. A. Mesa, O A. Lopez, C. P. Poole, Jr., and R. J. Creswick, Physical Review, B44, 7297 (1991).
  • "ESR Evidence for an incommensurate Phase in Doped KH2PO4, " (with H. A. Farach, C. P. Poole, Jr., and R. J. Creswick), Ferroelectrics, 120, 49 (1991).
  • "Equilibrium Domain Configuration in KDP-type Ferroelectrics," with H. A. Farach and C. P. Poole, Jr., Ferroelectrics, 157, 51 (1994).