Volume 88, Number 2, October 2009
Article Number 20011
Number of page(s) 5
Section General
Published online 10 November 2009
EPL, 88 (2009) 20011
DOI: 10.1209/0295-5075/88/20011

Environment-induced entanglement in a refined weak-coupling limit

F. Benatti1, 2, R. Floreanini2 and U. Marzolino1, 2

1   Dipartimento di Fisica Teorica, Università di Trieste - 34014 Trieste, Italy, EU
2   Istituto Nazionale di Fisica Nucleare, Sezione di Trieste - 34014 Trieste, Italy, EU

received 12 August 2009; accepted in final form 12 October 2009; published October 2009
published online 10 November 2009

Two non-directly interacting qubits with equal frequencies can become entangled via a Markovian, dissipative dynamics through the action of a weakly coupled Ohmic heat bath. In the standard weak-coupling limit derivation, this purely dissipative effect disappears if the frequencies are different because of the “ergodic average” used by this approach. However, there are physical situations where this technique is too rough to capture all the relevant aspects of the dissipative dynamics. In these cases, in order to better describe the physical behavior of the open system, it is necessary to go beyond the “ergodic average”. We show that, in this more refined framework, the entanglement capability of the environment persists also in the case of different frequencies.

03.67.Bg - Entanglement production and manipulation.
03.65.Yz - Decoherence; open systems; quantum statistical methods.

© EPLA 2009