Numerical Simulation of the Nernst Effect in Extreme Type-II Superconductors: A Negative Nernst Signal and its Noise Power Spectra

TL;DR

This paper uses numerical simulations to study the Nernst effect in extreme type-II superconductors, revealing a sign reversal of the thermoelectric coefficient near the transition temperature and analyzing its noise spectrum to understand vortex dynamics.

Contribution

It presents the first numerical simulation of the Nernst effect in extreme type-II superconductors, showing sign reversal of alpha_xy and proposing noise analysis to distinguish vortex regimes.

Findings

Sign reversal of alpha_xy near the mean-field transition temperature.

Noise power spectrum exhibits 1/f^beta behavior.

Proposes experimental method to analyze vortex dynamics.

Abstract

Recently, different transport coefficients have been measured in High-Tc superconductors to pinpoint the nature of the pseudogap phase. In particular, the thermoelectric coefficients received a considerable attention both theoretically and experimentally. We numerically simulate the Nernst effect in extreme type-II superconductors using the time-dependent Ginzburg-Landau equations. We report the sign reversal of the thermoelectric coefficient, alpha_xy, at temperatures close to the mean-field transition temperature, Tc^{MF}(H), which qualitatively agrees with recent experiments on high-Tc materials. We also discuss the noise power spectrum of alpha_xy, which shows 1/f^beta behavior. Based on this observation, we propose an experiment to distinguish among different regimes of vortex dynamics by measuring the noise correlations of the Nernst signal.