Quantum effects in thermal conduction: Nonequilibrium quantum discord and entanglement

We study the process of heat transfer through an entangled pair of two-level systems, demonstrating the role of quantum correlations in this nonequilibrium process. While quantum correlations generally degrade with increasing the temperature bias, introducing spatial asymmetry leads to an intricate behavior: connecting the qubits unequally to the reservoirs, one finds that quantum correlations persist and increase with the temperature bias when the system is more weakly linked to the hot reservoir. In the reversed case, linking the system more strongly to the hot bath, the opposite, more natural behavior is observed, with quantum correlations being strongly suppressed upon increasing the temperature bias.