Eur. Phys. J. D 61, 199-205 (2011)
https://doi.org/10.1140/epjd/e2010-00230-5

Robust stationary entanglement of two coupled qubits in independent environments

¹ Dipartimento di Scienze Fisiche ed Astronomiche dell'Università di Palermo, via Archirafi 36, 90123 Palermo, Italy
² CNR, CNISM, via Archirafi 36, 90123 Palermo, Italy
³ Departamento de Óptica, Facultad de Física, Universidad Complutense, 28040 Madrid, Spain

Corresponding author: ^a rosanna@fisica.unipa.it

Received: 6 May 2010
Published online: 14 September 2010

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.