Topological phase transition in quantum-heat-engine cycles

Abstract

We explore signatures of a topological phase transition (TPT) in the work and efficiency of a quantum heat engine, which uses a single layer topological insulator, stanene, in an external electric field as a working substance. The magnitude of the electric field controls the trivial and topological insulator phases of the stanene. The effect of TPT is investigated in two types of thermodynamic cycles, with and without adiabatic stages. We examine a quantum Otto cycle for the adiabatic and an idealized Stirling cycle for the non-adiabatic case. In both cycles, investigations are done for high and low temperatures. It is found that Otto cycle can distinguish the critical point of the TPT as an extremum point in the work output with respect to applied fields at all temperatures. Stirling cycle can identify the critical point of the TPT as the maximum work point with respect to the applied fields only at relatively lower temperatures. As temperatures increase towards the room temperature maximum work point of the Stirling cycle shifts away from the critical point of the TPT. In both cycles, increasing the temperature causes considerable enhancement in work and efficiency from the order of meV to eV.

Spin quantum heat engines with shortcuts to adiabaticity

“…Accordingly, many proposals to realize them can be found in the literature [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], some of which take into account finite-time engine cycles [22][23][24][25][26]. In addition, the effects of the profound quantum nature of the QHE such as such as cooperativity [27][28][29][30][31], coherence and correlations [32][33][34] on the performance of QHEs have also been investigated. Following the demonstration of a singleion engine cycle [35], genuine QHE experiments have been reported [36] with a single spin in a nuclear magnetic resonance (NMR) set up [36,37], a cold Rb atom [38], and an nitrogen-vacancy (NV) center in diamond [39].…”

ZnO microparticle‐loaded chitosan/poly(vinyl alcohol)/acacia gum nanosphere‐based nanocomposite thin film wound dressings for accelerated wound healing

“…It was clearly observed that cells quite well penetrated into the inner walls of pores and the surface of the scaffolds by forming layers between the spherical structures of the nanocomposite films. Higher roughness as nanospherical structures of the film may have a critical role on improving the attachment and spreading of the cells . Spherical structures of PC8A2%0.4ZnO nanocomposite film and nesting fibroblasts between these structures were seen clearly in the SEM micrograph of the PC8A2%0.4ZnO.…”

Quantum thermodynamics and quantum coherence engines

“…Other potential impact of quantum fuels can be envisioned in the fields of quantum batteries [204,205], and thermal quantum annealing [205][206][207] or error correction [115]. Besides, it can be a promising direction to explore quantum fuels for topological quantum heat engines [208,209]. Optimization of quantum thermodynamical processes and quantum thermal machines, in general, can benefit from quantum machine learning methods [210].…”