Anisotropy and Magnetic Field Effects on the Entanglement of a Two Qubit Heisenberg XY Chain

Authors

G. Lagmago Kamta, University of Nebraska - Lincoln
Anthony F. Starace, University of Nebraska-LincolnFollow

Date of this Version

March 2002

Comments

Published by American Physical Society. Phys. Rev. Lett. 88, 107901 (2002). http://prl.aps.org. Copyright © 2002 American Physical Society. Permission to use.

Abstract

We investigate the entanglement of a two-qubit anisotropic Heisenberg XY chain in thermal equilibrium at temperature T in the presence of an external magnetic field B along the z axis. By means of the combined influences of anisotropic interactions and a magnetic field B, one is able to produce entanglement for any finite T, by adjusting the magnetic field strength. This contrasts with the isotropic interaction or the B = 0 cases, for which there is no entanglement above a critical temperature T_c that is independent of the external B field.