Quantum heat valve and diode of strongly coupled defects in amorphous material

The mechanical strain can control the frequency of two-level atoms inamorphous material. In this work, we would like to employ two coupled two-levelatoms to manipulate the magnitude and direction of heat transport bycontrolling mechanical strain to realize the function of a thermal switch andvalve. It is found that a high-performance heat diode can be realized in thewide Piezo voltage range at different temperatures. We also discuss thedependence of the rectification factor on temperatures and couplings of heatreservoirs. We find that the higher temperature differences correspond to thelarger rectification effect. The asymmetry system-reservoir coupling strengthcan enhance the magnitude of heat transfer, and the impact of asymmetric andsymmetric coupling strength on the performance of the heat diode iscomplementary. It may provide an efficient way to modulate and control heattransport's magnitude and flow preference. This work may give insight intodesigning and tuning quantum heat machines.