Superconductivity

A. Houghton, R.A. Pelcovits, A. Sudb, "Flux lattice melting in high-Tc] superconductors," Physical Review B, 40, 6763-70, 1 October 1989.

Anthony Houghton (Brown University, Providence, R.I.): "Many potential applications of the high-Tc superconductors demand high critical currents. Classical type II superconductors--for example, niobium--in a magnetic field are well described by A.A. Abrikosov's mean field theory as a lattice of rigid vortex lines, each carrying one quantum of magnetic flux. The formation of such a lattice is of obvious importance because it allows relatively few pinning centers to pin all of the flux lines, allowing dissipationless current flow. In our paper, we showed that several, not-unrelated, material properties conspire to allow large thermal fluctuations of the vortex positions: short superconducting coherence length, high temperature, and extreme material anisotropy. A simple criterion shows that these thermal fluctuations soften the vortex lattice, which `melts' at a temperature, Tm, much lower than the zero...