Magnetization vector in the reversible region of a highly anisotropic cuprate superconductor: anisotropy factor and the role of 2D vortex fluctuations

TL;DR

This study investigates the magnetization vector in a highly anisotropic cuprate superconductor, revealing the influence of 2D vortex fluctuations and estimating a high anisotropy factor of about 190.

Contribution

It provides experimental analysis of the magnetization vector components in Tl-2223, incorporating thermal 2D vortex fluctuations into the London-like model, and estimates the anisotropy factor.

Findings

Angular dependence matches London-like model with vortex fluctuations

Estimated anisotropy factor is approximately 190

Thermal 2D vortex fluctuations significantly influence magnetization

Abstract

By using a high quality Tl2Ba2Ca2Cu3O10 (Tl-2223) single crystal as an example, the magnetization vector was probed in the reversible region of highly anisotropic cuprate superconductors. For that, we have measured its components along and transverse to the applied magnetic field for different crystal orientations. The analysis shows that the angular dependence of the perpendicular component of the magnetization vector follows the one predicted by a London-like approach which includes a contribution associated with the thermal fluctuations of the 2D vortex positions. For the Tl-2223 crystal studied here, a lower bound for the anisotropy factor was estimated to be about 190.