Previous Page  |  Table of Contents  |  Next Page

Keith Olive, Principal Investigator

Monte-Carlo Study of Vortex Phase Diagram in Layered Superconductors

Thermodynamics and transport properties of Type II superconductors in magnetic field are essentially properties of the vortex matter. A peculiarity of high Tc superconductors is a very high amplitude of thermal fluctuations in the vortex state. This leads to destruction of the low temperature vortex crystal state well below the mean field upper critical field. The only way to obtain quantitative information about the phase diagram in the vortex state is large scale numerical simulations.

These researchers have used the supercomputing resources of the Supercomputing Institute to study the phase diagram by Monte-Carlo simulations of the three-dimensional uniformly frustrated XY model. The properties of the melting transition have been investigated for different anisotropy parameters. This study shows that the pancake alignment above the melting transition increases with decreasing of the anisotropy. At high anisotropies, the melting is accompanied by a significant drop in the coupling energy and the destruction of vortex lines, while at small anisotroppies, the vortex lines preserve their continuity at the melting transition. In the linelike melting regime, several universal properties of the transition and of the liquid phase are found. These properties include the scaling of the melting temperature with anisotropy and magnetic field, the effective line tension of vortices in the liquid regime, the latent heat, the entropy jump per entanglement length, and relative jump of Josephson energy at the transition as compared to the latent heat.

This information is available in alternative formats upon request by individuals with disabilities. Please send email to alt-format@msi.umn.edu or call 612-624-0528.

HOME | QUESTIONS | FEEDBACK
Employment | Events | Links | People | Programs | Publications | Support | Welcome