Statistical Mechanics of Vortices in Type-II Superconductors

Thermal fluctuations and disorder play an essential role in high-T$_c$ superconductors. After reviewing the mean-field phase diagram we describe significant modifications that result when the effects of finite temperature and disorder are incorporated. Thermal fluctuations cause the melting of the Abrikosov flux line lattice into a vortex liquid at high temperatures, and disorder produces novel glass phases at low temperatures. We analyze phase transitions between these new phases and describe transport properties in various regimes.