  We study the optimal teleportation based on Bell measurements via the thermal
states of a two-qubit Heisenberg XXX chain in the presence of
Dzyaloshinsky-Moriya (DM) anisotropic antisymmetric interaction and obtain the
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 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.
