Optimal teleportation via thermal entangled states of a two-qubit Heisenberg chain

¹  State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences - P. O. Box 912, Beijing 100083, China
²  School of Physics, Beijing University of Aeronautics & Astronautics - Xueyuan Road No. 37, Beijing 100083, China
³  School of Mathematics, Physics and Informatics, Xinjiang Normal University - Urumchi 830054, China

Corresponding author: gf1978zhang@buaa.edu.cn

Received: 17 October 2008
Accepted: 22 May 2009

Abstract

We study the optimal teleportation based on Bell measurements via the thermal states of a two-qubit Heisenberg XXX chain in the presence of the Dzyaloshinsky-Moriya (DM) anisotropic antisymmetric interaction and obtain an optimal unitary transformation. The explicit expressions of the output state and the teleportation fidelity are presented and compared with those of the standard protocol. It is shown that in this protocol the teleportation fidelity is always larger and the unit fidelity is achieved at zero temperature. The DM interaction can enhance the teleportation fidelity at finite temperatures, as opposed to the effect of the interaction in the standard protocol. Cases with other types of anisotropies are also discussed.