Universal two-level quantum Otto machine under a squeezed reservoir

Quantum thermodynamic devices: from theoretical proposals to experimental reality

“…However, the idea of modifying ideal, classical cycles to harness quantum resources has proven to be versatile and powerful, see, for instance, an engine operating with transmon qubits 41 . More importantly, we will see in the following that heat engines operating with nonequilibrium or squeezed reservoirs [42][43][44][45][46][47][48][49][50][51][52][53][54] also follow essentially the same design principles.…”

“…The proof of concept experiments of a quantum Otto heat engine realized with NMR demonstrated their versatility of investigating the thermodynamic properties as well as the irreversibility of thermal devices. The NMR set up has recently been used to shed more light on understanding the performance of quantum engines with engineered reservoirs 54,286 as well as experimentally demonstrating the influence of fluctuations in quantum heat engines 287 .…”

Quantum thermodynamics aspects with a thermal reservoir based on $\mathcal{PT}$-symmetric Hamiltonians

“…Other proposals, however, have also considered non-classical effects in thermal reservoir models to obtain advantages. A well-known example is that of a squeezed thermal reservoir [49], employed to derive a generalized Carnot bound [50] as well as in quantum Otto cycles [51][52][53]. In this case, it is also possible to write an effective temperature depending on the squeezing parameter r, given by T eff = T 0 cosh (2r) [51].…”

Unified trade-off optimization of quantum harmonic Otto engine and refrigerator

“…Due to its simplicity and amenability to analytical results, a quantum Otto cycle, whose working substance is a time-dependent single harmonic oscillator, has become a standard model to investigate the performance characteristics of thermal devices [14,19,[33][34][35][36][37][38][39][40][41][42][43]. Further, the recent experimental realization of a nanoscale harmonic Otto heat engine provides us with better motivation to study its thermodynamic performance in great detail [44].…”