Influence of dephasing on the entanglement teleportation via a two-qubit Heisenberg XYZ system
Quantum Optics Group, Department of Physics, University of
Isfahan, Hezar Jarib
Received in final form: 16 January 2011
Published online: 25 March 2011
We study the entanglement dynamics of an anisotropic two-qubit Heisenberg XYZ system in the presence of intrinsic decoherence. The usefulness of such a system for performance of the quantum teleportation protocol and entanglement teleportation protocol is also investigated. The results depend on the initial conditions and the parameters of the system. The roles of system parameters such as the inhomogeneity of the magnetic field b and the spin-orbit interaction parameter D, in entanglement dynamics and fidelity of teleportation, are studied for both product and maximally entangled initial states of the resource. We show that for the product and maximally entangled initial states, increasing D amplifies the effects of dephasing and hence decreases the asymptotic entanglement and fidelity of the teleportation. For a product initial state and specific interval of the magnetic field B, the asymptotic entanglement and hence the fidelity of teleportation can be improved by increasing B. The XY and XYZ Heisenberg systems provide a minimal resource entanglement, required for realizing efficient teleportation. Also, in the absence of the magnetic field, the degree of entanglement is preserved for the maximally entangled initial states . The same is true for the maximally entangled initial states , in the absence of spin-orbit interaction D and the inhomogeneity parameter b. Therefore, it is possible to perform quantum teleportation protocol and entanglement teleportation , with perfect quality, by choosing a proper set of parameters and employing one of these maximally entangled robust states as the initial state of the resource.
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2011