Sufficient Conditions for Thermal Rectification in Hybrid Quantum Structures

We analytically identify sufficient conditions for manifesting thermal rectification in two-terminal junctions, including a subsystem connected to two reservoirs, within the quantum master equation formalism. We recognize two classes of rectifiers. In type A rectifiers, the reservoirs' energy structure is dissimilar. In type B rectifiers, the baths are identical but include particles whose statistics differ from that of the subsystem, to which they asymmetrically couple. Our study applies to various hybrid junctions including metals, dielectrics, and spins.