四能级量子制冷循环

A four-level quantum refrigeration cycle

本文提出以两个qubit量子纠缠系统为工质的四能级制冷循环模型,基于量子热力学第一定律和热纠缠概念,分析了在循环中系统与外界交换的热量、输入功、制冷系数等热力学参数与量子纠缠之间的关系,结果表明:制冷系数等高线图是环状曲线,随纠缠比r增加而非单调变化;当相互作用常数J比较小时,量子制冷机运行区间在c_1>c_2,当增加J值时,制冷机运行区间在c_1>c_2和c_1<c_2两个区域;最大制冷系数ε_(max)随J值增大而增加.

A four-level entangled quantum refrigeration cycle working with a two-qubit entangled system is proposed in this paper.Based on the first law of quantum thermodynamics and the concept of thermal entanglement,the relation between the quantum entanglement and the several thermodynamic quantities such as the heat transfer,the input work and the coefficient of performance is analyzed.It is found that the isoline of the coefficient of performance is the loop line and it no longer monotonically changes with the ratio of entanglement;in a small exchange constant J the operation region of the refrigerator is c1 〉 c2 and in a larger exchange constant J the operation region of the refrigerator may be c1 〉 c2 or c1 〈c2;the maximal coefficient of performance increases as the exchange constant increases.