https://doi.org/10.1140/epjd/e2013-30435-9
Regular Article
Thermal tripartite quantum correlations: quantum discord and entanglement perspectives
1
Research Institute for Fundamental Sciences, University of
Tabriz, 51666-14766
Tabriz,
Iran
2
Department of Theoretical Physics and Astrophysics, University of
Tabriz, 51666-14766
Tabriz,
Iran
a
e-mail: n.behzadi@tabrizu.ac.ir
Received: 13 July 2012
Received in final form: 25 December 2012
Published online: 4 June 2013
We investigate thermal tripartite quantum correlations for a spin star network and for a new extended version of it. In a spin star network, three peripheral spins interact with the central spin identically while in extended spin star network, three peripheral spins interact with two central spatially separated spins in the same way. We exploit the method of [C.C. Rulli, M.S. Sarandy, Phys. Rev. A 84, 042109 (2011)] to evaluate the tripartite quantum discord (TQD) and the method of [M. Li, S. Fei, Z. Wang, Rep. Math. Phys 65, 289 (2010)] called as lower bound of tripartite concurrence (LBTC) to evaluate the tripartite entanglement (TE) of the the peripheral parties in both systems. It is found that thermal TQD is much more robust than thermal TE as a function of temperature T. Also, the peripheral parties of the extended spin star network, in comparison with those of the spin star one, can exhibit higher values of TQD at T > 0. This, indeed, motivates us to realise improved quantum information and quantum computation tasks at finite temperatures.
Key words: Quantum Information
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2013
