Vortex Glass Transition in High Tc Superconductor

H-T phase diagram and the nature of Vortex-glass phase in a quasi two-dimensional superconductor: Sn metal layer sandwiched between graphene sheets

The magnetic properties of a quasi two-dimensional superconductor, Sn-metal graphite (MG), are studied using DC and AC magnetic susceptibility. Sn-MG has a unique layered structure where Sn metal layer is sandwiched between adjacent graphene sheets. This compound undergoes a superconducting transition at Tc = 3.75 K at H = 0. The H-T diagram of Sn-MG is similar to that of a quasi two-dimensiona...

Vortex Phases in Condensed Matter and Cosmology

Placing a high-Tc superconductor in an increasing external magnetic field, the flux first penetrates the sample through an Abrikosov vortex lattice, and then a first order transition is observed by which the system goes to the normal phase. We discuss the cosmological motivation for considering the electroweak phase transition in the presence of an external magnetic field, the analogies this sy...

Correlation Lengths in the Vortex Line Liquid of a High-Tc Superconductor

We use the three dimensional uniformly frustrated XY model as a model for a high temperature superconductor in an applied magnetic field and explicitly measure the longitudinal correlation length jz in the vortex line liquid phase. We determine the scaling of jz with magnetic field and system anisotropy close to the vortex lattice melting transition. We apply our results to determine the extent...

Absence of a phase transition in a three-dimensional vortex glass model with screening.

We study the gauge glass model for the vortex glass transition in type– II superconductors, including screening of the interaction between vortices. From the size dependence of the domain wall energy we find that, in two– dimensions, the transition is at T = 0 both with and without screening but the exponents are different in the two cases. In three-dimensions, we find that screening destroys t...

Vortex-Glass Melting Transition and Scaling Behavior in the Cuprate Superconductor Nd2-xCexCuOy at Low Temperatures