TRANSITION BETWEEN FLUX LIQUID AND FLUX SOLID IN HIGH-TC SUPERCONDUCTORS

We have studied flux melting near the Hc1 line in T-Ba-Cu-O using a variational Monte Carlo method. The existence of a flux-liquid phase has been observed and the transition line between flux liquid and flux solid in the H-T phase diagram has been determined. The width of the liquid phase increases with temperature as T2 at low temperatures, as predicted by Nelson, and faster than T2 at higher temperatures, eventually crossing over to the high-field melting curve. © 1990 The American Physical Society.