论文标题
第14组的弯曲单层中的旋转分裂和自旋霍尔电导率：第一原理计算
Spin splitting and spin Hall conductivity in buckled monolayers of the group 14: First-principles calculations
论文作者
论文摘要
已知该组14组的元素单层，即具有弯曲的蜂窝结构，即硅，德国烯，Stanene和铅烯，可以证明，由于电场与高对称轴平行的电场平行，这表明了旋转分裂，该轴能够在量子旋转霍尔绝缘子和普通带绝缘子之间调谐其拓扑相之间的拓扑相。我们基于密度函数理论执行第一原理计算，以量化自旋依赖性带隙和自旋分裂作为应用电场的函数，并提取不变型汉密尔顿的主要系数。使用线性响应理论和Wannier插值方法，我们计算单层中的自旋霍尔电导率，并研究其对外部电场的敏感性。我们的结果表明，随着电场逆转带隙并将单层将单层带入琐碎阶段时，旋转厅电导率尚未量化，并且在硅，德国烯和Stanene的情况下显着降解。在铅烯的情况下，电场诱导的带隙并未闭合，铅烯显示出对外部电场的旋转电导率。
Elemental monolayers of the group 14 with a buckled honeycomb structure, namely silicene, germanene, stanene, and plumbene, are known to demonstrate a spin splitting as a result of an electric field parallel to their high symmetry axis which is capable of tuning their topological phase between a quantum spin Hall insulator and an ordinary band insulator. We perform first-principles calculations based on the density functional theory to quantify the spin-dependent band gaps and the spin splitting as a function of the applied electric field and extract the main coefficients of the invariant Hamiltonian. Using the linear response theory and the Wannier interpolation method, we calculate the spin Hall conductivity in the monolayers and study its sensitivity to an external electric field. Our results show that the spin Hall conductivity is not quantized and in the case of silicene, germanene, and stanene degrades significantly as the electric field inverts the band gap and brings the monolayer into the trivial phase. The electric field induced band gap does not close in the case of plumbene which shows a spin Hall conductivity that is robust to the external electric field.
