关键词: 几何失协/
共生度/
两量子比特模型
English Abstract
Thermal geometric discords in a two-qubit Heisenberg XY model
Fan Hong-Rui,Yuan Ya-Li,
Hou Xi-Wen
1.Department of Physics, Huazhong Normal University, Wuhan 430079, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant No. 11174099).Received Date:03 June 2016
Accepted Date:15 August 2016
Published Online:05 November 2016
Abstract:We study the influences of the external magnetic field, temperature, and coupling parameter on the thermal quantum correlation in a two-qubit Heisenberg XY model, where the correlation is described in terms of two modified geometric discords and concurrence. It is shown that those three quantities behave similarly in the regions of lower temperature and weak magnetic field. However, the two geometric discords are more robust against temperature and magnetic field than the concurrence. Moreover, two geometric discords exhibit different behaviors under suitable conditions, that is, one discord increases as the magnetic field rises whereas the other discord decreases. In particular, the discord reveals the phenomenon of sudden change, while neither of other discord and concurrence displays such a phenomenon.
Keywords: geometric discords/
concurrence/
two-qubit model
