Nonlinear thermal and thermoelectric transport from quantum geometry

TL;DR

This paper explores how nonlinear thermal and thermoelectric responses reveal detailed aspects of quantum geometry, connecting these responses to known physical relations and implications for topological materials.

Contribution

It uncovers new links between nonlinear thermal/thermoelectric responses and quantum geometry, extending the understanding of topological systems.

Findings

Nonlinear responses probe Berry curvature and quantum metric dipoles.

Connections between thermal responses and Wiedemann-Franz and Mott relations.

Implications for topological materials like Weyl-Kondo semimetals and bilayer graphene.

Abstract

Quantum geometry may enable the development of quantum phases ranging from superconductivity to correlated topological states. One powerful probe of quantum geometry is the nonlinear Hall response which detects Berry curvature dipole in systems with time-reversal invariance and broken inversion symmetry. With broken time-reversal symmetry, this response is also associated with quantum metric dipole. Here we investigate nonlinear thermal and thermoelectric responses, which provide a wealth of new information about quantum geometry. In particular, we uncover a web of connections between these quantities that parallel the standard Wiedemann-Franz and Mott relations. Implications for the studies of a variety of topological systems, including Weyl-Kondo semimetals and Bernal bilayer graphene, are discussed.