Tan Xiao-Dong, Kang Xiu-Bao, Zhao Li-Min, Zhang Jun-Ji, Hao Hao-Shan
School of Science, Henan Institute of Engineering, Zhengzhou 451191, People's Republic of China.
J Phys Condens Matter. 2019 May 22;31(20):205602. doi: 10.1088/1361-648X/ab071c. Epub 2019 Feb 14.
Based on the effective spin-ladder model, we study the properties of quantum dissonance (Q) between two edge spins in chiral graphene nanoribbons (CGNRs) thermalized with a reservoir at temperature T, and discuss the influences of relative location between two edge spins, ribbon width, temperature, and on-site Coulomb repulsion (U) on Q. The results show that Q is widely present in Wannier edge states. For intra-edge coupled spin pairs, quantum entanglement (E) is zero, but there still exists considerable value of Q. Interestingly, Q always keeps a constant for entangled edge spin pairs. Considering the thermal effect, it shows that Q always decays with the increasing temperature T, and the decay rate is very sensitive to the intensity of U. Compared Q with E and total quantum correlation (quantum discord, denoted by D), we conjecture that the quantum correlations for a bipartite Wannier edge state in CGNRs satisfy the relation Q ⩽ D-E.
基于有效的自旋梯子模型，我们研究了在温度T下与热库热化的手性石墨烯纳米带（CGNRs）中两个边缘自旋之间的量子失谐（Q）特性，并讨论了两个边缘自旋之间的相对位置、带宽度、温度和在位库仑排斥（U）对Q的影响。结果表明，Q广泛存在于万尼尔边缘态中。对于边缘内耦合的自旋对，量子纠缠（E）为零，但仍存在相当大的Q值。有趣的是，对于纠缠的边缘自旋对，Q始终保持恒定。考虑热效应，结果表明Q总是随着温度T的升高而衰减，并且衰减率对U的强度非常敏感。将Q与E和总量子关联（量子失协，用D表示）进行比较，我们推测CGNRs中二分万尼尔边缘态的量子关联满足关系Q⩽D - E。
