Nonlinear phenomena in quantum thermoelectrics and heat

TL;DR

This paper reviews recent advances in understanding nonlinear quantum transport phenomena in nanostructures driven by thermal gradients, emphasizing theoretical approaches, experimental findings, and future research directions.

Contribution

It provides a comprehensive overview of nonlinear thermoelectric and heat transport in quantum systems, highlighting differences from linear response and discussing recent experimental and theoretical developments.

Findings

Nonlinear effects significantly influence thermoelectric efficiency.

Experimental evidence of strong thermal biases in quantum dots and molecular junctions.

Theoretical predictions of heat rectification and Kondo effect under nonlinear conditions.

Abstract

We review recent developments in nonlinear quantum transport through nanostructures and mesoscopic systems driven by thermal gradients or in combination with voltage biases. Low-dimensional conductors are excellent platforms to analyze both the thermoelectric and heat dynamics beyond linear response because due to their small size a small temperature difference applied across regions gives rise to large thermal biases. We offer a theoretical discussion based on the scattering approach to highlight the differences between the linear and the nonlinear regimes of transport. We discuss recent experiments on quantum dots and molecular junctions subjected to strong temperature differences. Theoretical predictions concerning the Kondo effect and heat rectification proposals are briefly examined. An important issue is the calculation of thermoelectric efficiencies including nonlinearities. Cross Seebeck effects and nonlinear spin filtering arise in superconductors and topological insulators while mixed noises between charge and heat currents are also considered. Finally, we provide an outlook on the possible future directions of the field.