Quantum Kinetic Theory of Nonlinear Nernst Effect

TL;DR

This paper develops a quantum kinetic theory to explain the nonlinear Nernst effect, introducing a new thermoelectric Berry curvature dipole that influences thermoelectric transport in time-reversal invariant materials.

Contribution

It presents a quantum kinetic framework for the nonlinear Nernst effect and introduces the concept of thermoelectric Berry curvature dipole, expanding understanding beyond semiclassical approaches.

Findings

Thermoelectric Berry curvature dipole induces nonlinear thermoelectric transport.

The theory applies to topological crystalline insulators with tilted Dirac cones.

Nonlinear Nernst effect can occur in time-reversal invariant materials.

Abstract

For a long period of time, we have been seeking how Berry curvature influnces the transport properties in materials breaking time-reversal symmetry. In time-reversal symmetric material, there will be no thermoelectric current induced by Berry curvature in linear regime. However, the nonlinear Hall current can be shown in non-magnetic and non-centrosymmetric materials, where Berry curvature dipole plays an important role. Most studies are developed from semi-classical Boltzmann equation. Here we show the quantum kinetic theory for nonlinear Nernst effect and introduce a new type of Berry curvature dipole: thermoelectric Berry curvature dipole. This new Berry curvature dipole will also induce the thermoelectric transport in nonlinear regime even in time-reversal invariant crystals. We will also apply our theory to topological crystalline insulator with tilted Dirac cone.