Phase diagram of high-T-c superconductors: Influence of anisotropy and disorder

[摘要] We propose a phase diagram for the vortex structure of high-temperature superconductors which incorporates the effects of anisotropy and disorder. It is based on numerical simulations using the three-dimensional Josephson-junction array model. We support the results with an estimation of the internal energy and configurational entropy of the system. Our results give a unified picture of the behavior of the vortex lattice, from the very anisotropic Bi2Sr2CaCu2O8 to the less anisotropic YBa2Cu3O7, and from the first-order melting ocurring in clean samples to the continuous transitions observed in samples with defects.

[关键词] HIGH-TEMPERATURE SUPERCONDUCTORS;LATTICE-MELTING TRANSITION;ABRIKOSOV VORTEX LATTICE;IRREVERSIBILITY LINE;SINGLE-CRYSTALS;ELASTIC THEORY;FLUX LATTICES;BI2SR2CACU2O8;YBA2CU3O7-DELTA;DIMENSIONALITY