Concurrent intersection point of magnetization and magneto-conductivity curves in strongly fluctuating superconductors

TL;DR

This paper investigates the intersection points of magnetization and magneto-conductivity curves in strongly fluctuating layered superconductors, explaining their occurrence through non-Gaussian thermal fluctuations and dimensional crossover effects.

Contribution

It provides a theoretical explanation for the simultaneous intersection points in magnetization and magneto-conductivity curves in high-temperature cuprate superconductors.

Findings

Intersection points occur at similar temperatures for magnetization and conductivity.

Strong thermal fluctuations with interactions cause the intersection points.

Dimensional crossover from 2D to 3D is crucial for the phenomenon.

Abstract

The thermal fluctuations contribution to magnetization and magneto-conductivity of type II layered superconductor is calculated in the framework of Lawrence-Doniach model. For numerous high temperature cuprate superconductors, it was discovered that the magnetization dependence on temperature in wide range of fields exhibits an intersection point at a temperature slightly below $T_{c}$. We notice a similar intersection point of the magneto-conductivity curves at the approximate same temperature. The phenomenon is explained by strong (non-gaussian) thermal fluctuations with interactions treated using a self-consistent theory. All higher Landau levels should be included. Dimensionality of the fluctuations is defined and the 2D-3D dimensional crossover is the key for the existence of intersection points.