Possible Nonlinear Anomalous Thermoelectric Effect in Organic Massive Dirac Fermion System

TL;DR

This paper introduces a new nonlinear thermoelectric effect called the nonlinear anomalous Ettingshausen effect in organic Dirac fermion systems, demonstrating its properties and relation to existing effects.

Contribution

It proposes the nonlinear AEE as a novel thermoelectric phenomenon in inversion-asymmetric conductors, specifically in organic massive Dirac fermion systems, expanding understanding of thermoelectric effects.

Findings

Nonlinear AEE generates a transverse heat current with rectifying, unidirectional behavior.

The effect appears at zero magnetic field in alpha-(BEDT-TTF)2I3.

It is related to the nonlinear anomalous Hall effect observed in the same material.

Abstract

We propose a novel current-induced thermoelectric phenomenon, the nonlinear anomalous Ettingshausen effect (AEE), at zero magnetic field in inversion-asymmetric conductors. As an example, we discuss the weak charge ordering state in a layered organic conductor alpha-(BEDT-TTF)2I3, which is a two-dimensional massive Dirac fermion system with a pair of tilted Dirac cones. The nonlinear AEE is a thermoelectric analogue of the nonlinear anomalous Hall effect, which is recently observed in alpha-(BEDT-TTF)2I3, and these two effects generally appear simultaneously. The nonlinear AEE generates a transverse heat current, which exhibits rectifying characteristics, namely unidirectionality even under an AC current.