Nearly perfect quantum thermal diode based on a strongly dispersive coupling magnon-qubit system

Abstract A quantum thermal diode based on strong dispersive coupling between a magnon and a qubit is proposed and analysed. The system utilizes a direct dispersive interaction that leads to asymmetric energy transitions, enabling controllable directional heat flow. Detailed numerical simulations demonstrate the occurrence of nearly perfect rectification under appropriate parameter conditions, with the rectification factor approaching unity in both resonant and off-resonant regimes. Results reveal that factors such as coupling strength, magnon anisotropy, and energy detuning significantly influence both heat current and rectification performance. While increased dispersive coupling enhances both heat transfer and rectification efficiency, purely coherent or combined coupling configurations are shown to degrade performance. Comparative analysis with existing thermal diode models highlights the superior performance of the proposed system, especially its ability to achieve nearly perfect rectification while maintaining appreciable heat currents. This work presents a feasible platform for designing efficient quantum heat management devices.