# Thermoelectric inversion in a resonant quantum dot-cavity system in the steady-state regime

## TL;DR

This paper explores how a photon cavity influences thermoelectric currents in a quantum dot system, revealing photon-induced effects, current inversion, and control over current magnitude and direction in steady-state conditions.

## Contribution

It demonstrates the impact of photon replica states and Rabi-splitting on thermoelectric transport, introducing a novel photon-controlled inversion mechanism.

## Key findings

- Photon replica states contribute to transport regardless of thermal gradient direction.
- A current plateau appears in the off-resonance regime at strong electron-photon coupling.
- Photon field can invert the thermoelectric current's sign and alter its magnitude.

## Abstract

The thermoelectric effect in a quantum dot system connected to two electron reservoirs in the presence of a photon cavity is investigated using a quantum master equation in the steady-state regime. If a quantized photon field is applied to the quantum dot system, an extra channel, the photon replica states, are formed leading to a generation of a photon-induced thermoelectric current. We observe that the photon replica states contribute to the transport irrespective of the direction of the thermal gradient. In the off-resonance regime, when the photon energy is smaller than the energy difference between the lowest states of the quantum dot system, a current plateau is seen for strong electron-photon coupling. In the resonant regime, an inversion of thermoelectric current emerges due to the Rabi-splitting. Therefore, the photon field can change both the magnitude and the sign of the thermoelectric current induced by the temperature gradient in the absence of a voltage bias between the leads.