Systematic study on stanene bulk states and the edge states of its zigzag nanoribbon
Systematic study on stanene bulk states and the edge states of its zigzag nanoribbon
复制标题
锯齿形纳米带锡烯体态及其边缘态的系统研究
DOI：
10.1088/1367-2630/aa8c46
复制
发表时间：
2017-11-01
影响因子：
3.3
通讯作者：
Liu, Cheng-Cheng
中科院分区：
文献类型：
--
作者：
Fu, Botao;Abid, M.;Liu, Cheng-Cheng
锡烯是石墨烯的对应物，但具有更大的自旋轨道耦合（SOC）强度，最近已通过实验合成。基于第一原理计算和有效模型，我们系统地研究了块体锡烯在垂直电场和双轴应变下的电子和拓扑性质，这些可以由衬底自然引入。我们发现，在临界垂直电场下会发生拓扑非平凡-平凡转变，而在临界双轴应变下会发生绝缘体-金属转变。我们还系统地研究了锯齿形纳米带的边缘态。我们发现拓扑边缘态具有很强的非线性色散，这与之前过于简化的紧束缚（TB）模型不同。建立了一个更加实用的 TB 模型，它很好地捕捉了边缘态的强非线性色散。我们详细研究了锯齿形带边缘态的四种磁性配置，发现边缘原子磁性的出现和磁化方向对自旋电流承载边缘通道有显着影响。此外，通过施加横向电场可以在锡烯纳米带中诱导半金属态，并且可以通过反转电场方向来选择相反的自旋通道。我们的研究结果对锡烯和其他相关屈曲系统的未来研究和应用具有指导意义。
Stanene, as a counterpart of graphene, but with much larger spin-orbit coupling (SOC) strength, has recently been synthesized experimentally. Based on first principle calculations and an effective model, we systematically study the electronic and topological properties of bulk stanene under vertical electric field and biaxial strain, which can be naturally introduced by substrates. We find that a topological nontrivial-trivial transition occurs under a critical vertical electric field and an insulator-metal transition happens under critical biaxial strains. We also systematically study the edge state of zigzag nanoribbons. We find that the topological edge state has strong nonlinear dispersion that is different from the previous oversimplified tight-binding (TB) model. A much more practical TB model is built, which captures the strongly nonlinear dispersion of the edge states very well. We investigate four magnetic configurations of the zigzag ribbon edge states in detail and find that the emergence of magnetism for the edge atoms and the magnetization direction have a remarkable impact on the spin-current-carrying edge channels. Furthermore, a half-metallic state can be induced in stanene nanoribbons by applying a transverse electric field, and opposite spin channels can be chosen by reversing the electric field direction. Our results are instructive for future research and applications on stanene and other related buckled systems.