Quantum Bipolar Thermoelectricity

Abstract: Thermoelectricity usually originates from energy-dependent transport asymmetries. In this Letter, we explore a purely quantum thermoelectric effect rooted in the emission/absorption asymmetry of a low-temperature quantum bath. We propose a gap-asymmetric S-I-S' superconducting tunnel junction in thermal equilibrium, coupled to a low-temperature electromagnetic environment, which develops a nonlinear quantum bipolar thermoelectric effect due to the dynamical Coulomb blockade. Key performance features are analyzed for realistic implementations.