Optimal teleportation via thermal entangled states of a two-qubit Heisenberg chainYue Zhou1, Guo-Feng Zhang2, Shu-Shen Li1 and Ahmad Abliz3
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
received 17 October 2008; accepted in final form 22 May 2009; published June 2009
published online 17 June 2009
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.
03.67.Hk - Quantum communication.
75.10.Jm - Quantized spin models.
© EPLA 2009