Entanglement Evolution in the Presence of Decoherence

Authors

Jin Wang, University of Nebraska - LincolnFollow
Herman Batelaan, University of Nebraska - LincolnFollow
Jeremy Podany, University of Nebraska - Lincoln
Anthony F. Starace, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

September 2006

Comments

Posted to arXiv.org September 6, 2006. Published in Journal of Physics B, 39, pp. 4343-4353 (2006). Copyright © 2006 IOP Publishing Ltd. Used by permission. http://www.iop.org/EJ/abstract/0953-4075/39/21/001

Abstract

The entanglement of two qubits, each defined as an effective two-level, spin 1/2 system, is investigated for the case that the qubits interact via a Heisenberg XY interaction and are subject to decoherence due to population relaxation and thermal effects. For zero temperature, the time dependent concurrence is studied analytically and numerically for some typical initial states, including a separable (unentangled) initial state. An analytical formula for non-zero steady state concurrence is found for any initial state, and optimal parameter values for maximizing steady state concurrence are given. The steady state concurrence is found analytically to remain non-zero for low, finite temperatures. We also identify the contributions of global and local coherence to the steady state entanglement.