一维XXZ环形自旋链中的量子关联

研究了系统尺度L=8的一维XXZ环形自旋链中的两体和多体量子纠缠以及两体量子失协，在这个过程中，充分考虑了温度和粒子间隔对纠缠和量子失谐的影响．结果发现，同种情况下，三体和四体纠缠比两体的更加“强壮”，且在低温条件下，利用多体纠缠可以探测到系统发生量子相变的临界点．与纠缠相比，量子失谐可以在较高温度下存在，且在相变点处总是表现出尖峰行为，这使得量子失谐在探测相变点方面更具优越性．

Quantum Correlations in One-dimensional Ring XXZ Spin Chain

The paper studies pair-wise and multiple quantum entanglement and pair-wise quantum discord in one-dimensional ring XXZ spin chain whose system scale L equals 8, and takes full account of the effects of temperature and particle interval on quantum entanglement and quantum discord in this process. The results show that three- and four-qubit entanglement are more ＂robust＂ than the pair-wise one under the same conditions, and the critical points on which the system produces quantum phase transitions can be detected through the multiple entanglement at low temperatures. Compared with the quantum entanglement, the quantum discord not only can survive at higher temperatures but also always shows cusp-like behavior at the phase transition point, which endows it with more advantages in the detection of the phase transition point.