近日，中国科学院物理研究所的曹俊鹏及其研究小组与彭桓武高能基础理论研究中心的杨文力等人合作并取得一项新进展。经过不懈努力，他们对具有可积开边界场XYZ自旋链的表面能和元激发进行了研究。相关研究成果已于2024年10月10日在国际知名学术期刊《高能物理杂志》上发表。

该研究团队研究了具有非对角可积开放边界条件的，各向异性XYZ自旋链的热力学极限。尽管U(1)对称性被打破，但通过采用新的参数化方案，研究人员精确得到了系统的表面能和激发能，从而解决了非均匀T-Q关系中的难题。

在使哈密顿量保持厄米的边界参数区域内，研究人员获得了基态和激发态转移矩阵本征值的零点分布模式。研究人员发现，由于体积中存在长程尼尔序，表面能和激发能依赖于位点数N的奇偶性。他们研究了所有边界参数区域的易轴和热力学极限。此外，通过取三角极限，研究人员还获得了边界XXZ模型热力学极限下的物理量。

附：英文原文

Title: Surface energy and elementary excitations of the XYZ spin chain with integrable open boundary fields

Author: Xin, Zhirong, Cao, Junpeng, Yang, Wen-Li, Wang, Yupeng

Issue&Volume: 2024-10-10

Abstract: We study the thermodynamic limit of the anisotropic XYZ spin chain with non-diagonal integrable open boundary conditions. Although the U(1)-symmetry is broken, by using the new parametrization scheme, we exactly obtain the surface energy and the excitation energy of the system, which has solved the difficulty in the inhomogeneous T Q relation. With the boundary parameters in the regions making the Hamiltonian Hermitian, we have obtained the distribution patterns of the zeros of the eigenvalue of the transfer matrix for the ground state and the excited ones. We find that the surface and excitation energies depend on the parities of sites number N, due to the long-range Neel order in the bulk. The easy-axis and thermodynamic limit for all the regions of boundary parameters are studied. We also obtain the physical quantities in the thermodynamic limit of boundary XXZ model by taking the trigonometric limit.

DOI: 10.1007/JHEP10(2024)090

Source: https://link.springer.com/article/10.1007/JHEP10(2024)090