Azizi Farshad, Rezania Hamed
Department of Physics, Jundi-Shapur University of Technology, Dezful, Iran.
Department of Physics, Razi University, Kermanshah, Iran.
Sci Rep. 2025 Jul 2;15(1):22815. doi: 10.1038/s41598-025-06018-5.
We investigate here the impact of an out-of-plane magnetic field and spin-orbit interaction on the spin conductivity of the two-dimensional Heisenberg model on a Lieb lattice. In this study, the Hamiltonian of the spin model has been transformed into a strongly interacting bosonic gas using a hard boson transformation. In this transformation, the occupation of a boson at each site is restricted by adding a hard core repulsion. To determine the excitation spectrum of the mapped model, the Green's function method has been employed. Based on the spectrum of the bosonic gas, the two-particle Green's function related to the spin conductivity of the two-dimensional Heisenberg model has been calculated. Computational results indicate that with an increase in the strength of the Dzyaloshinskii-Moriya interaction, the peak position in the dynamic spin conductivity shifts to higher frequencies under a constant magnetic field. However, the magnetic field does not affect the peak position of the dynamic spin conductivity. On the other hand, the intensity of dynamic spin conductivity increases with the strength of the Dzyaloshinskii-Moriya interaction. Our findings suggest that for a range of values of Dzyaloshinskii-Moriya interaction strength, the static transverse structure factor continuously decreases with the magnetic field. Additionally, for each value of the magnetic field, the temperature dependence of the static spin conductivity of localized electrons on the lattice exhibits a limited temperature peak.
我们在此研究面外磁场和自旋轨道相互作用对利布晶格上二维海森堡模型自旋电导率的影响。在本研究中，自旋模型的哈密顿量已通过硬玻色子变换转化为强相互作用玻色气体。在这种变换中，通过添加硬核排斥来限制每个格点上玻色子的占据数。为了确定映射模型的激发谱，采用了格林函数方法。基于玻色气体的谱，计算了与二维海森堡模型自旋电导率相关的两粒子格林函数。计算结果表明，在恒定磁场下，随着Dzyaloshinskii-Moriya相互作用强度的增加，动态自旋电导率的峰值位置向更高频率移动。然而，磁场并不影响动态自旋电导率的峰值位置。另一方面，动态自旋电导率的强度随Dzyaloshinskii-Moriya相互作用强度的增加而增大。我们的研究结果表明，对于一系列Dzyaloshinskii-Moriya相互作用强度值，静态横向结构因子随磁场持续减小。此外，对于每个磁场值，晶格上局域电子的静态自旋电导率的温度依赖性呈现有限温度峰值。
