Heat current through an artificial Kondo impurity beyond linear response

TL;DR

This paper explores the nonlinear heat current behavior in a strongly interacting quantum dot within the Kondo regime, revealing symmetry properties and nonlinear effects at voltages below the Kondo temperature.

Contribution

It introduces a detailed analysis of heat current symmetry and nonlinear effects in a Kondo quantum dot beyond linear response using slave-boson mean-field theory.

Findings

Heat current exhibits symmetry properties under bias reversal.

Nonlinear effects appear at voltages below the Kondo temperature.

Transmission function depends on both energy and voltage.

Abstract

We investigate the heat current of a strongly interacting quantum dot in the presence of a voltage bias in the Kondo regime. Using the slave- boson mean-field theory, we discuss the behavior of the energy flow and the Joule heating. We find that both contributions to the heat current dis- play interesting symmetry properties under reversal of the applied dc bias. We show that the symmetries arise from the behavior of the dot trans- mission function. Importantly, the transmission probability is a function of both energy and voltage. This allows us to analyze the heat current in the nonlinear regime of transport. We observe that nonlinearities ap- pear already for voltages smaller than the Kondo temperature. Finally, we suggest to use the contact and electric symmetry coefficients as a way to measure pure energy currents.