Heat asymmetries in nanoscale conductors: The role of decoherence and inelasticity

TL;DR

This paper explores heat flow asymmetries in nanoscale conductors with inelastic scattering, revealing differences between electric and contact asymmetries in nonlinear regimes and their relation to the Seebeck coefficient.

Contribution

It introduces a theoretical framework for analyzing heat asymmetries in interacting coherent conductors with inelastic effects, highlighting differences in asymmetries beyond linear response.

Findings

In linear regime, heat asymmetries are proportional to the Seebeck coefficient.

In nonlinear regime, electric and contact asymmetries diverge depending on bias.

Results align with recent experimental measurements of heat asymmetries.

Abstract

We investigate the heat flow between different terminals in an interacting coherent conductor when inelastic scattering is present. We illustrate our theory with a two-terminal quantum dot setup. Two types of heat asymmetries are investigated: electric asymmetry $\Delta_E$, which describes deviations of the heat current in a given contact when voltages are exchanged, and contact asymmetry $\Delta_C$, which quantifies the difference between the power measured in two distinct electrodes. In the linear regime, both asymmetries agree and are proportional to the Seebeck coefficient, the latter following at low temperature a Mott-type formula with a dot transmission renormalized by inelasticity. Interestingly, in the nonlinear regime of transport we find $\Delta_E\neq\Delta_C$ and this asymmetry departure depends on the applied bias configuration. Our results may be important for the recent experiments by Lee et al. [Nature (London) 498, 209 (2013)], where these asymmetries were measured.