Abstract
We investigate the entanglement of a two-qubit anisotropic Heisenberg chain in thermal equilibrium at temperature in the presence of an external magnetic field along the axis. By means of the combined influences of anisotropic interactions and a magnetic field , one is able to produce entanglement for any finite , by adjusting the magnetic field strength. This contrasts with the isotropic interaction or the cases, for which there is no entanglement above a critical temperature that is independent of the external field.
- Received 28 September 2001
DOI:https://doi.org/10.1103/PhysRevLett.88.107901
©2002 American Physical Society