量子电子学报, 2018, 35 (4): 444, 网络出版: 2018-08-24
外磁场下具有Dzyaloshinski-Moriya作用的海森堡链中的热纠缠
Thermal entanglement in Heisenberg chain with Dzyaloshinski-Moriya interaction in external magnetic fields
量子光学 热纠缠 并发度 海森堡XXZ链 DM相互作用 非均匀磁场 quantum optics thermal entanglement concurrence Heisenberg XXZ chain DM-interaction nonuniform magnetic field
摘要
详细分析了DM 相互作用常数D、 温度T、 均匀磁场B、 非均匀磁场b、 自旋耦合常数J 和各向异性参数Δ对热纠缠度C的影响。结果表明: 虽然T 和B 升高使纠缠度C 变小,但D增大使C变大,而且它会使磁场阈值Bt 变大。当B>|Bt|和B<|Bt| 时,b对C的影响不同。对比发现,B和b 对于J、Δ (JΔ>0) 区域纠缠存在的面积变化的影响以及C的影响也不同。另外,当T升高时,B 和b 存在热纠缠范围的变化规律 也不尽相同。因此,即使在强外磁场及高温环境等恶劣条件下,也可以通过调节B、b、J、D、T和Δ 来控制热纠缠。这些结论在固态系统 量子信息研究中有一定应用价值。
Abstract
Influences of the Dzyaloshinskii-Moriya(DM) coupling constant D, temperature T, uniform external magnetic field B, nonuniform magnetic field b, real coupling constant J and anisotropic parameter Δ on the thermal entanglement concurrence C are investigated in detail. Results show that both the increasing of T and B decrease C, but the increasing of D develops C, and D can also heighten the magnetic field threshold Bt. When B is bigger or less than Bt, b has different influence on C. By comparison, it is found that the B and b have different effects on the area about J and Δ (JΔ>0) where exists thermal entanglement as well as on C. What’s more, as T increases, the variation rule of the range of B in which exists thermal entanglement is different from b. As a result, the thermal entanglement can be controlled by adjusting the values of B, b, J, D, T and Δ in various terrible environments, such as strong external magnetic field, or high temperature environment, which is useful in the research of quantum information in solid systems.
黄利元, 方卯发. 外磁场下具有Dzyaloshinski-Moriya作用的海森堡链中的热纠缠[J]. 量子电子学报, 2018, 35(4): 444. HUANG Liyuan, FANG Maofa. Thermal entanglement in Heisenberg chain with Dzyaloshinski-Moriya interaction in external magnetic fields[J]. Chinese Journal of Quantum Electronics, 2018, 35(4): 444.