Seminar 4/13: Superconductor Theory for Poets, Pedestrians And Others: Old Theory, New Theory, Room Temperature Possibilities

Department of Chemical Engineering
West Virginia University

Seminar

Superconductor Theory for Poets, Pedestrians And Others: Old Theory, New Theory, Room Temperature Possibilities

Dr. Richard H. Squire
Department of Chemistry
WVU Institute of Technology
Montgomery, WV

ABSTRACT

We begin with a cartoon illustrating the heart of all superconductivity, namely how two electrons bind together to produce a dissipation-less current. The discussion evolves into the general features of superconductors, such as a working definition (the Meissner effect) and flux quantization (a macroscopic manifestation of quantum mechanics). Several years prior to the advent of the Bardeen, Cooper, Schrieffer (BCS) microscopic theory of superconductivity in 1956, Ginsburg and Landau (GL) invented a phenomenological free energy theory that explained superconductivity as it was known at the time. In addition, the GL theory explains many other phase transitions such as vapor condensing into a liquid in addition to the one involving superconductivity. The order parameter in the GL theory turns out to be identical to the long range order exhibited in superconductivity.

As in earlier BCS theory, high temperature superconductors (including one compound with a transition temperature of 135C) also have paired electrons. Therefore, while this may be the only common fact between the two types of SC's, almost all evidence suggests that the microscopic solution of this perplexing problem will generate a new era in physics and chemistry. Nobel Laureate Anderson's famous quote, "More is different," is discussed in this context. The prospects for a room temperature superconductor are reviewed.

No prior knowledge is required concerning superconductivity; all terms are defined such that a poet or pedestrian could follow many of the arguments.

Friday, April 13, 2007 9:30am - 10:45am
Room 401, Engineering Sciences Building
Refreshments will be served at 9:15 am

Questions or Directions call: 304-293-2111, ext. 2418.

04/13/2007