The thermal quantum discord （QD） is studied in a two-qubit Heisenberg XXZ system with DzyaloshinskiiMoriya （DM） interaction. We compare the thermal QD with thermal entanglement in this system and find remarkable d...The thermal quantum discord （QD） is studied in a two-qubit Heisenberg XXZ system with DzyaloshinskiiMoriya （DM） interaction. We compare the thermal QD with thermal entanglement in this system and find remarkable differences between them. For instance, we show situations where QD decreases asymptotically to zero with temperature T while entanglement decreases to zero at the point of critical temperature, situations where QD decreases with certain tunable parameters such as Dx and Dx when entanglement increases. We find that the characteristic of QD is exotic in this system and this possibly offers a potential solution to enhance entanglement of a system. We also show that tunable parameter Dx is more efficient than parameter Dz in most regions for controlling the QD.展开更多
A new type of deformed XXZ model was constructed and diagonalized by the coordinate Bethe ansatz method. We obtained the energy and the Bethe ansatz equations of the model and also discussed some thermodynamics of the...A new type of deformed XXZ model was constructed and diagonalized by the coordinate Bethe ansatz method. We obtained the energy and the Bethe ansatz equations of the model and also discussed some thermodynamics of the model.展开更多
The thermal entanglement of a two-qutrit spin-1 anisotropic Heisenberg XXZ chain in an inhomogeneous magnetic field is studied in detail. The effects of the external magnetic field （B）, a parameter b which controls ...The thermal entanglement of a two-qutrit spin-1 anisotropic Heisenberg XXZ chain in an inhomogeneous magnetic field is studied in detail. The effects of the external magnetic field （B）, a parameter b which controls the inhomogeneity of B, and the bilinear interaction parameters Jx = Jy ≠ Jz on the thermal variation of the negativity are studied in detail. It is found that negativity N decreases when the values of magnetic field, inhomogeneity b and temperature are increasing. In addition, N remains at higher temperatures for higher values of Jz and lower values of B and b.展开更多
The Berezinskii-Kosterlitz-Thouless phase transition of spin-1/2 XXZ chain is reinvestigated by the quantum Fisher information.Quantum Fisher informations of the whole N sites and the partial N/3 sites display remarka...The Berezinskii-Kosterlitz-Thouless phase transition of spin-1/2 XXZ chain is reinvestigated by the quantum Fisher information.Quantum Fisher informations of the whole N sites and the partial N/3 sites display remarkably similar behaviors near the critical point.The critical exponent of quantum Fisher information is obtained as β=0.47,which is consistent with the results obtained by the concurrence and quantum discord.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.90503009,10775116973 Program under Grant No.2005CB724508
文摘The thermal quantum discord （QD） is studied in a two-qubit Heisenberg XXZ system with DzyaloshinskiiMoriya （DM） interaction. We compare the thermal QD with thermal entanglement in this system and find remarkable differences between them. For instance, we show situations where QD decreases asymptotically to zero with temperature T while entanglement decreases to zero at the point of critical temperature, situations where QD decreases with certain tunable parameters such as Dx and Dx when entanglement increases. We find that the characteristic of QD is exotic in this system and this possibly offers a potential solution to enhance entanglement of a system. We also show that tunable parameter Dx is more efficient than parameter Dz in most regions for controlling the QD.
基金The project supported by National Natural Science Foundation of China under Grant No. 90403019
文摘A new type of deformed XXZ model was constructed and diagonalized by the coordinate Bethe ansatz method. We obtained the energy and the Bethe ansatz equations of the model and also discussed some thermodynamics of the model.
文摘The thermal entanglement of a two-qutrit spin-1 anisotropic Heisenberg XXZ chain in an inhomogeneous magnetic field is studied in detail. The effects of the external magnetic field （B）, a parameter b which controls the inhomogeneity of B, and the bilinear interaction parameters Jx = Jy ≠ Jz on the thermal variation of the negativity are studied in detail. It is found that negativity N decreases when the values of magnetic field, inhomogeneity b and temperature are increasing. In addition, N remains at higher temperatures for higher values of Jz and lower values of B and b.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11065005 and 11365006the Innovation Team Foundation of the Education Department of Guizhou Province under Grant No.[2014]35
文摘The Berezinskii-Kosterlitz-Thouless phase transition of spin-1/2 XXZ chain is reinvestigated by the quantum Fisher information.Quantum Fisher informations of the whole N sites and the partial N/3 sites display remarkably similar behaviors near the critical point.The critical exponent of quantum Fisher information is obtained as β=0.47,which is consistent with the results obtained by the concurrence and quantum discord.
