Quantum heat engine model of mixed triangular spin system as a working substance

In this work, we consider a Heisenberg XXZ mixed (1∕2,1,1∕2) spin system on a triangular cell. We briefly summarize the theoretical framework. Then, we compute the energy eigenvalues for all eigenstates of the Hamiltonian model and we set a four-stroke Otto cycle to depend on the thermodynamical cycle based on the theoretical framework. In the numerical procedure, based on eigenenergies of the system, we compute the work and the efficiency for different spin interaction couplings for the four-stroke quantum Otto cycle. We show that the Heisenberg XXZ mixed spin model produce positive work and efficiency, when the system is coupled to an oscillating heat bath reservoir. Finally, we investigate magnetic field dependence of the work for several spin coupling and discuss all the results.