Effects of photon field on heat transport through a quantum wire attached to leads

Abstract

We theoretically investigate photo-thermoelectric transport through a quantum wire in a photon cavity coupled to electron reservoirs with different temperatures. Our approach, based on a quantum master equation, allows us to investigate the influence of a quantized photon field on the heat current and thermoelectric transport in the system. We find that the heat current through the quantum wire is influenced by the photon field resulting in a negative heat current in certain cases. The characteristics of the transport are studied by tuning the ratio, $\hbarω_γ / k_{\rm B} ΔT$, between the photon energy, $\hbarω_γ$, and the thermal energy, $k_{\rm B} ΔT$. The thermoelectric transport is enhanced by the cavity photons when $k_{\rm B} ΔT > \hbarω_γ$. By contrast, if $k_{\rm B} ΔT < \hbarω_γ$, the photon field is dominant and a suppression in the thermoelectric transport can be found in the case when the cavity-photon field is close to a resonance with the two lowest one-electron states in the system. Our approach points to a new technique to amplify thermoelectric current in nano-devices.

RevTeX, 7 pages with 8 included eps figures