Quantum thermodynamics in superconducting circuits*

Quantum thermodynamics has become a field of increasing importance in recent years, the understanding of heat transport at the quantum limit, having broad ranging applications, for example in circuit QED experiments, and nanoscale physics.

By integrating the tools of ultra-sensitive microwave bolometry with those of superconducting circuits (qubits), we present a platform for investigating fundamental quantum thermodynamics in mesoscopic systems, and our initial experimental realizations.

We will present recent observations of flux-tunable photonic heat transport between thermal baths embedded in both equal (quantum heat valve) and unequal (quantum heat engine) resonant environments interfaced by a transmon qubit. We demonstrate that the coupling to the qubit mediates the interface between the classical and quasi-Hamiltonian regime for this transport in the static-flux limit [1], and present our initial findings for a driven-flux system.

[1] Ronzani et al, Nature Phys (2018)