Entanglement in the three-qubit Heisenberg model with next nearest neighbor interaction and a nonuniform magnetic field
Physics Department, School of Science, Tianjin University, 300072, Tianjin, P.R. China
Corresponding author: a firstname.lastname@example.org
Revised: 17 October 2006
Published online: 15 December 2006
Pairwise thermal entanglement in the three-qubit XXX Heisenberg model with next nearest neighbor interaction and a nonuniform magnetic field has been studied. It's found that the next nearest neighbor interaction has a great effect on the entanglement between the next nearest neighbor sites, but has slight effect on the nearest neighbor entanglement (NNE). Applying a magnetic field at the middle site enhances the next nearest neighbor entanglement (NNNE) sharply when there is a small field at the side sites and the next nearest neighbor coupling constant is positive. A staggered magnetic field helps to maintain nearest neighbor entanglement obviously.
PACS: 42.50.Dv – Nonclassical states of the electromagnetic field, including entangled photon states; quantum state engineering and measurements / 03.67.-a – Quantum information / 03.65.Ud – Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006