Fast Route to Thermalization

Abstract

We present a control scheme for quantum systems coupled to a thermal bath. We demonstrate state-to-state control between two Gibbs states. This scheme can be used to accelerate thermalization and cool the open system. Starting from a microscopic description, we derive the reduced system dynamics, leading to a non-adiabatic master equation. The equation contains non-trivial effects due to the non-adiabatic driving and bath interaction. These special features enable controlling the open system and accelerating the entropy changes. For a two-level system model, we obtain a general solution and introduce a reverse-engineering scheme for control. The control problem is analyzed in the context of the theory of quantum control and the accompanying thermodynamic cost.

Speed-ups to isothermality: Enhanced quantum thermal machines through control of the system-bath coupling

“…Particularly relevant are shortcuts to adiabaticity (STA), which speed up unitary (and hence closed-system) evolutions [11], making them suited to improve the adiabatic part of thermodynamic cycles [12][13][14]. For open quantum systems, speed-ups of the evolution to a particular target state [15][16][17][18], such as an equilibration or thermalization process [19][20][21][22][23][24], have also been developed. For classical systems, such equilibration speed-ups (the so-called Engineered Swift Equilibration [25][26][27]) have been experimentally tested [25,26].…”

“…In general, such speed-ups are possible by adding a time-dependent term to the Hamiltonian which, in the presence of a thermal bath, leads to a new source of dissipation. Indeed, speedups of equilibration and thermalization generally come with an extra work cost [21,24,25,33] (see also the discussion in [35] for thermodynamic computing).…”