2016/05/01 by Gil Katz, Ronnie Kosloff · 3 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Amplitude #Coupling (piping) #Heat current #Heat engine #Heat exchanger #Quantum many-body systems #Quantum thermodynamics #Refrigeration #Spins #Thermal reservoir #quant-ph #stochastic dynamics and bifurcation
paper · pdf · doi:10.3390/e18050186
published as Entropy 2016, 18(5), 186
arxiv created 2016/05/01 · openalex publication_date 2016/05/16 · arxiv updated 2016/06/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The performance characteristics of a heat rectifier and a heat pump are studied in a non-Markovian framework. The device is constructed from a molecule connected to a hot and cold reservoir. The heat baths are modelled using the stochastic surrogate Hamiltonian method. The molecule is modelled by an asymmetric double-well potential. Each well is semi-locally connected to a heat bath composed of spins. The dynamics are driven by a combined system–bath Hamiltonian. The temperature of the baths is regulated by a secondary spin bath composed of identical spins in thermal equilibrium. A random swap operation exchange spins between the primary and secondary baths. The combined system is studied in various system–bath coupling strengths. In all cases, the average heat current always flows from the hot towards the cold bath in accordance with the second law of thermodynamics. The asymmetry of the double well generates a rectifying effect, meaning that when the left and right baths are exchanged the heat current follows the hot-to-cold direction. The heat current is larger when the high frequency is coupled to the hot bath. Adding an external driving field can reverse the transport direction. Such a refrigeration effect is modelled by a periodic driving field in resonance with the frequency difference of the two potential wells. A minimal driving amplitude is required to overcome the heat leak effect. In the strong driving regime the cooling power is non-monotonic with the system–bath coupling.