Quantum effects in thermal conduction: Nonequilibrium quantum discord and entanglement

TL;DR

This paper investigates how quantum correlations like discord and entanglement influence heat transfer in a two-qubit system under nonequilibrium conditions, revealing that asymmetry in reservoir coupling can sustain or enhance quantum correlations.

Contribution

It demonstrates the impact of spatial asymmetry on quantum correlations during heat transfer, showing that weaker coupling to the hot reservoir can preserve or increase quantum correlations with temperature bias.

Findings

Quantum correlations degrade with temperature bias in symmetric setups.

Asymmetry in reservoir coupling can sustain or enhance quantum correlations.

Quantum correlations are suppressed when the system is strongly linked to the hot reservoir.

Abstract

We study the process of heat transfer through an entangled pair of two-level system, 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.