Chin. Phys. B, 2008, Vol. 17(2): 702-709    DOI: 10.1088/1674-1056/17/2/057
 CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES Prev   Next

# Quantum communication in spin star configuration

Deng Hong-Liang, Fang Xi-Ming
Key Laboratory of Quantum Structure and Quantum Control of Ministry of Education and Department of Physics, Hunan Normal University, Changsha 410081, China
Abstract  This paper considers a generalized spin star system which can be solved exactly, with the central spin-$\ddfrac{1}{2}$ system embedded in an outer ring of $N$ spin-$\ddfrac{1}{2}$ particles(denoted as spin bath). In this model, in addition to the central-outer interaction, each pair of nearest neighbour of the bath interacts within themselves. The general expressions of the eigenstates as well as the eigenvalues of the model are derived with the use of the symmetries of system. It analyses the quantum state transfer and the dynamical behaviour of entanglement created during quantum communication. It also analyses the efficiency of the configuration regarded as quantum phase covariant clone or decoherence model. Some interesting results are discovered concerning the properties of quantum communication in this model.
Keywords:  phase covariant clone      entanglement dynamics      quantum state transfer
Received:  19 April 2007      Revised:  22 June 2007      Published:  20 February 2008
 PACS: 03.67.Hk (Quantum communication) 03.67.Mn (Entanglement measures, witnesses, and other characterizations) 03.65.Ud (Entanglement and quantum nonlocality)
Fund: Project supported by the National Science Foundation (Grant No 2007CB925204).