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

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. Copyright (C) EPLA, 2009

National Science Foundation of China 10604053 1087401310664004Beihang Lantian Project National Basic Research Program of China (973 Program) G2009CB929300 National Natural Science Foundation of China 60821061 60776061This work is supported by the National Science Foundation of China under Grant No. 10604053 & 10874013 and the Beihang Lantian Project. Sh-ShL also acknowledges the support of the National Basic Research Program of China (973 Program) Grant No. G2009CB929300 and the National Natural Science Foundation of China under Grant Nos. 60821061 & 60776061. AA also acknowledges the support of the National Science Foundation of China under Grant No. 10664004.