Quantum memory enhanced dissipative entanglement creation in non-equilibrium steady states

TL;DR

This paper explores how quantum memory effects influence the creation of entangled non-equilibrium steady states in a heat-reservoir-coupled qubit system, revealing conditions that guarantee entanglement via heat current.

Contribution

It introduces a collision model with environmental memory effects showing their role in expanding entanglement conditions and increasing concurrence in dissipative steady states.

Findings

Memory effects broaden entanglement parameter space.

Memory effects increase achievable concurrence.

Heat current range guarantees entanglement.

Abstract

This Article investigates dissipative preparation of entangled non-equilibrium steady states (NESS). We construct a collision model where the open system consists of two qubits which are coupled to heat reservoirs with different temperatures. The baths are modeled by sequences of qubits interacting with the open system. The model can be studied in different dynamical regimes: with and without environmental memory effects. We report that only a certain bath temperature range allows for entangled NESS. Furthermore, we obtain minimal and maximal critical values for the heat current through the system. Surprisingly, quantum memory effects play a crucial role in the long time limit. First, memory effects broaden the parameter region where quantum correlated NESS may be dissipatively prepared and, secondly, they increase the attainable concurrence. Most remarkably, we find a heat current range that does not only allow but guarantees that the NESS is entangled. Thus, the heat current can witness entanglement of non-equilibrium steady states.