Robust stationary entanglement of two coupled qubits in independent environments

TL;DR

This paper investigates how two coupled qubits maintain stationary entanglement in independent environments at nonzero temperatures, highlighting the role of counter-rotating terms and robustness against thermal noise.

Contribution

It demonstrates that counter-rotating terms induce stationary entanglement and analyzes its robustness, providing insights into entanglement persistence in realistic thermal conditions.

Findings

Stationary entanglement arises from counter-rotating interactions.

Entanglement remains detectable at practical temperatures.

Reservoir asymmetry influences entanglement dynamics.

Abstract

The dissipative dynamics of two interacting qubits coupled to independent reservoirs at nonzero temperatures is investigated, paying special attention to the entanglement evolution. The counter-rotating terms in the qubit-qubit interaction give rise to stationary entanglement, traceable back to the ground state structure. The robustness of this entanglement against thermal noise is thoroughly analyzed, establishing that it can be detected at reasonable experimental temperatures. Some effects linked to a possible reservoir asymmetry are brought to light.