Open AccessThermal geometric discords in a two-qubit Heisenberg XY model
Author(s) -
Fan Hong-Rui,
Ye Yuan,
Xi-Wen Hou
Publication year - 2016
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.65.220301
Subject(s) - physics , concurrence , quantum discord , thermal , magnetic field , phenomenon , qubit , condensed matter physics , field (mathematics) , quantum , quantum mechanics , quantum entanglement , thermodynamics , mathematics , pure mathematics
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.