Heat transport in a two-level system driven by a time-dependent temperature

Abstract

The field of thermotronics aims to develop thermal circuits that operate with temperature biases and heat currents just as how electronic circuits are based on voltages and electric currents. Here, we investigate a thermal half-wave rectifier based on a quantum two-level system (a qubit) that is driven by a periodically modulated temperature difference across it. To this end we present a nonequilibrium Green's function technique, which we extend to the time domain to account for the time-dependent temperature in one of two thermal reservoirs connected to the qubit. We find that the qubit acts a thermal diode in parallel with a thermal capacitor, whose capacitance is controlled by the coupling to the reservoirs. These findings are important for the efforts to design nonlinear thermal components such as heat rectifiers and multipliers that operate with more than one diode.

Energy dynamics, heat production and heat–work conversion with qubits: toward the development of quantum machines

“…In the context of qubits coupled to photonic baths thermal rectification was predicted in [329] and this effect was recently experimentally confirmed in [306] in the configuration where the qubit is coupled to resonators, which are in turn coupled to thermal baths at different temperatures. This experiment is briefly discussed in section 11.5 and already motivated several theoretical works [330][331][332][333]. This a difficult theoretical problem which requires the proper treatment of many-body physics along with far from equilibrium conditions, which must be solved approximately.…”

Energy dynamics, heat production and heat-work conversion with qubits: towards the development of quantum machines

“…This experiment is briefly discussed in Sec. 11.5 and already motivated several theoretical works [292,293,294,295]. This a difficult theoretical problem which requires the proper treatment of many-body physics along with far from equilibrium conditions, which must be solved approximately.…”

Engineering dynamical couplings for quantum thermodynamic tasks

“…Before closing, we comment on another relevant aspect for quantum devices, i.e. the possibility to achieve rectification of heat current flows [45,46,[81][82][83][84][85][86][87][88][89]. It has been shown recently that heat rectification can be obtained in a linear system (as a QHO) by relying on external time-dependent forces [74,90].…”