Tunable photonic heat transport in a quantum heat valve

Abstract

Quantum thermodynamics is emerging both as a topic of fundamental research and as means to understand and potentially improve the performance of quantum devices [1][2][3][4][5][6][7][8][9][10]. A prominent platform for achieving the necessary manipulation of quantum states is superconducting circuit quantum electrodynamics (QED) [11]. In this platform, thermalization of a quantum system [12][13][14][15] can be achieved by interfacing the circuit QED subsystem with a thermal reservoir of appropriate Hilbert dimensionality. Here we study heat transport through an assembly consisting of a superconducting qubit [16] capacitively coupled between two nominally identical coplanar waveguide resonators, each equipped with a heat reservoir in the form of a normal-metal mesoscopic resistor termination. We report the observation of tunable photonic heat transport through the resonator-qubit-resonator assembly, showing that the reservoir-to-reservoir heat flux depends on the interplay between the qubit-resonator and the resonator-reservoir couplings, yielding qualitatively dissimilar results in different coupling regimes. Our quantum heat valve is relevant for the realisation of quantum heat engines [17] and refrigerators, that can be obtained, for example, by exploiting the time-domain dynamics and coherence of driven superconducting qubits [18,19]. This effort would ultimately bridge the gap between the fields of quantum information and thermodynamics of mesoscopic systems. * alberto.ronzani@aalto.fi arXiv:1801.09312v3 [cond-mat.mes-hall]

Non-Markovian dynamics of a quantum heat engine: out-of-equilibrium operation and thermal coupling control

“…This is not only of pure theoretical interest but has immediate consequences in the context of recent progress in fabricating and controlling thermal quantum devices [6][7][8][9]. While the first heat engines implemented with trapped ions [10,11] or solid state circuits [12] still operated in the classical regime, more recent experiments entered the quantum domain [13][14][15][16]. In the extreme limit, the work medium may even consist of only a single quantum object [17].…”

Maximum power and corresponding efficiency for two-level heat engines and refrigerators: optimality of fast cycles

“…Quantum thermodynamics [6][7][8] has emerged both as a field of fundamental interest, and as a potential candidate to improve the performance of thermal machines [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The optimal performance of these systems has been discussed within several frameworks and operational assumptions, ranging from low-dissipation and slow driving regimes [24][25][26][27][28], to shortcuts to adiabaticity approaches [29][30][31][32], to endoreversible engines [33,34].…”

Rectification of heat currents across nonlinear quantum chains: a versatile approach beyond weak thermal contact

“…It is particularly interesting as it allows, by tuning the asymmetry either in the coupling to the reservoirs or in the onsite frequencies, to control the rectification of being positive or negative. This may be of relevance for experimental realizations of heat valves as they have very recently been explored in [41]. Underlying physical principles can be revealed already for a set-up consisting of two oscillators, where we keep frequency and coupling strength of the oscillator at site n=1 fixed and vary those at n=2, i.e.…”

“…One should note that the above averages are trace and noise moments which means that the respective currents in the bulk in (41) and (42) are determined by elements of the covariance matrix. The first terms in (43) and (44) represent system-bath correlations and have to be computed as elements of y (30) to obtain the covariance matrix.…”