Enhanced thermal entanglement in an anisotropic Heisenberg<i>XYZ</i>chain 论文

摘要

The thermal entanglement in the Heisenberg $\mathrm{XYZ}$ chain is investigated in the presence of an external magnetic field B. In the two-qubit system, the critical magnetic field ${B}_{c}$ is increased by introducing the interaction of the z component of two neighboring spins ${J}_{z}.$ This interaction not only improves the critical temperature ${T}_{c},$ but also enhances the entanglement for a particular fixed B. We also analyze the pairwise entanglement between nearest neighbors in three qubits. The pairwise entanglement, for a fixed T, can become strong by controlling B and ${J}_{z}.$