Quantum-dot circuit-QED thermoelectric diodes and transistors

Recent breakthroughs in quantum-dot circuit-quantum-electrodynamics systems are promising both from fundamental perspectives and from the point of view of quantum photonic devices. However, understanding such setups as potential thermoelectric devices has been missing. In this paper, via the Keldysh nonequilibrium Green's function approach, we show that cavity-coupled double quantum-dots can serve as excellent quantum thermoelectric diodes and transistors. Using an enhanced perturbation approach based on the exact polaron transformation, we find dependencies of thermoelectric transport properties on the electron-photon interaction beyond the predictions from the conventional second-order perturbation theory. In particular, strong light-matter interaction leads to pronounced rectification effects for both charge and heat, as well as thermal transistor effects in the linear transport regime, which opens up a cutting-edge frontier for quantum thermoelectric devices.