Thermal Entanglement Of Spin System With Dzialoshinski-Moriya Interaction

Quantum information and quantum computation, an interdisciplinary field which involves quantum mechanics, computer science and the theory of information, has attracted more and more interests. Quantum entanglement is a unique character of quantum system and it can be used not only for testing the basic problem of quantum mechanics but also for acting as an important resource of quantum information and quantum computation. In order to apply the quantum information processing into the reality, we need the extended and integrated systems. Spin system is such a solid system. Around a half century ago, Dzialoshinski and Moriya introduced anisotropic anti-symmetric exchange interaction, the DM interaction to explain weak ferromagnetism of anti-ferromagnetic crystals. In this paper, we study the effects of Dzyaloshinski- Moriya interaction on thermal entanglement in Heisenberg and Ising spin chain.Firstly, The effect of DM interaction on thermal entanglement of a two-qubit XXZ spin chain in a homogenous magnetic field is investigated. We investigate the effects of the DM interaction D , the magnetic field B , the anisotropyΔand the temperature T on the thermal entanglement. It is found that the DM interaction can enhance thermal entanglement. When the DM interaction D is large enough, the entanglement can exist for larger temperatures and strong magnetic field.Secondly, we study the effects of DM interaction on entanglement and teleportation in a two-qubit Ising system with intrinsic decoherence taken into account. It is found that for the maximally entangled initial state, DM interaction can't maintain the initial maximal values of entanglement N1 and fidelity F 1. But, DM interaction is benefit for entanglement and teleportation when the initial state is unentangled, because appropriate value of D can increase entanglement and fidelity.