Entanglement of Heisenberg XY model on inhomogeneous periodic chain

Abstract

Abstract:

The time evolution of entanglement and thermal entanglement of an isotropic XY model on the inhomogeneous chain is investigated when there is anisotropic magnetic field. Since entanglement is a very important recourse in the field of quantum information, the study of measure and time evolution of entanglement is necessary. We use the quantity of concurrence to theoretically calculate the entanglement, and analyze it by numerical simulations. If the external magnetic field is small and the nearest neighbor coupling is large, the concurrence oscillates between zero and one. If the external magnetic field is large and the nearest neighbor coupling is small, the maximum concurrence can be reduced and even disappears. Meanwhile, the entanglement decreases when the number of spins in the Heisenberg chain increases. The thermal entanglement drops quickly when the temperature increases. It decreases also as the external magnetic field increases. It can be increased if the inhomogeneity of the system is increased.

Key words: quantum optics, inhomogeneous Heisenberg chain, concurrence, time evolution of entanglement, thermal entanglement, external magnetic field

CLC Number:

O431.2

CHENG Ming, ZHU Shiqun. Entanglement of Heisenberg XY model on inhomogeneous periodic chain[J]. J4, 2012, 29(4): 448-456.

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