Coupled two-qubit engine and refrigerator in Heisenberg model

Abstract

We have considered two-qubit Heisenberg XYZ model subject to an external magnetic field in the presence of the Dzyaloshinskii–Moriya (DM) anisotropic antisymmetric interaction as the working substance of the quantum Otto cycle. At first, a scheme is proposed for thermalization where working substance of the quantum Otto cycle is induced in the presence decoherence. The net work input and the efficiency of the engine are calculated in terms of system parameters. We investigate the effects of (DM) anisotropic antisymmetric interaction and external magnetic field on processes of the Otto cycle. An interesting phenomenon that the model reveals the mode of the cycle is a refrigerator or a heat engine. The results also enable us to determine for some values of parameters, the system is suitable for heat engine or refrigerator. Moreover, we find instances of regimes that the mode of the cycle is neither a refrigerator nor a heat engine.