Nernst effect in the two-dimensional XY model

TL;DR

This paper calculates the Nernst signal in a 2D XY model, showing qualitative agreement with experimental data on high-Tc cuprates, and suggests vortex excitations as the cause of the anomalous Nernst effect.

Contribution

It provides a numerical calculation of the Nernst effect in the 2D XY model and links vortex excitations to experimental observations.

Findings

Nernst signal exhibits tilt-hill profile similar to experiments

Vortex and anti-vortex excitations are likely responsible for the Nernst effect

Results support vortex dynamics as key to understanding the anomalous Nernst effect

Abstract

We calculate the Nernst signal directly in the phenomenological two-dimensional XY model. The obtained numerical results are consistent with the experimental observations in some high-Tc cuprate superconductors qualitatively, where the vortex Nernst signal has a characteristic tilt-hill profile. It is suggested that the excitations of vortex and anti-vortex in 2D is the possible origin of the anomalous Nernst effect.