Two-dimensional easy-plane SU(3) magnet with the transverse field: anisotropy-driven multicriticality
Two-dimensional easy-plane SU(3) magnet with the transverse field: anisotropy-driven multicriticality
复制标题
DOI：
10.1088/1742-5468/abe412
复制
发表时间：
2021-02
期刊：
影响因子：
--
通讯作者：
Y. Nishiyama
中科院分区：
文献类型：
--
作者：
Y. Nishiyama
采用精确对角化方法研究了横向场作用下的二维易平面SU(3)磁体。到目前为止，对于XY模型（即易平面SU（2）磁体），用精确对角化方法研究了横向场驱动的有序无序相界，并声称XX对称点处的端点奇异性（多临界性）不符合大N理论的预测。为了协调这种差异，我们使用各向异性参数 η 将内部对称性扩展到易平面 SU(3)，从而平滑地插值各向同性 (η = 0) 和完全各向异性 (η = 1) 情况。作为初步调查，设置 η = 1，我们通过保真度敏感性 χ F 来分析有序-无序相变，该敏感性表现出明显的临界特征。因此，通过仔细缩放 η，将 χ F 数据代入交叉缩放公式以确定交叉指数 phi，这似乎反映了内部对称群向 SU(3) 的扩展。
The two-dimensional easy-plane SU(3) magnet subjected to the transverse field was investigated with the exact-diagonalization method. So far, as to the XY model (namely, the easy-plane SU(2) magnet), the transverse-field-driven order–disorder phase boundary has been investigated with the exact-diagonalization method, and it was claimed that the end-point singularity (multicriticality) at the XX-symmetric point does not accord with large-N-theory’s prediction. Aiming to reconcile the discrepancy, we extend the internal symmetry to the easy-plane SU(3) with the anisotropy parameter η, which interpolates the isotropic (η = 0) and fully anisotropic (η = 1) cases smoothly. As a preliminary survey, setting η = 1, we analyze the order–disorder phase transition through resorting to the fidelity susceptibility χ F, which exhibits a pronounced signature for the criticality. Thereby, with η scaled carefully, the χ F data are cast into the crossover-scaling formula so as to determine the crossover exponent ϕ, which seems to reflect the extension of the internal symmetry group to SU(3).