Melting of the Nanocrystalline Vortex Matter in Highly Anisotropic High-Temperature Superconductors

by Yadin Y. Goldschmidt & Eduardo Cuansing Physical Review Letters, 21 Oct 2005 Multilevel Monte Carlo simulations of the vortex matter in the highly anisotropic high-temperature superconductor Bi₂Sr₂CaCu₂O₈ were performed. We introduced low concentration of columnar defects satisfying Bphi<=B. Both the electromagnetic and Josephson interactions among pancake vortices were included. The nanocrystalline, nanoliquid, and homogeneous liquid phases were identified in agreement with experiments. We observed the two-step melting process and also noted an enhancement of the structure factor just prior to the melting transition. A proposed theoretical model is in agreement with our findings. Read more