Crasto de Lima F, Ferreira G J, Miwa R H
Instituto de Física , Universidade Federal de Uberlândia , C.P. 593, 38400-902 , Uberlândia , MG Brazil.
Nano Lett. 2019 Sep 11;19(9):6564-6568. doi: 10.1021/acs.nanolett.9b02802. Epub 2019 Aug 22.
Recently, orbital-textures have been found in Rashba and topological insulator (TI) surface states as a result of the spin-orbit coupling (SOC). Here, we predict a p/p orbital texture, in linear dispersive Dirac bands, arising at the /' points of χ- borophene chiral monolayer. Combining "first-principles" calculations with effective Hamiltonians, we show that the orbital pseudospin has its direction locked with the momentum in a similar way as TIs' spin-textures. Additionally, considering a layer pseudospin degree of freedom, this lattice allows stackings of layers with equivalent or opposite chiralities. In turn, we show a control of the orbital textures and layer localization through the designed stacking and external electric field. For instance, for the opposite chirality stacking, the electric field allows for an on/off switch of the orbital-textured Dirac cone.
最近，由于自旋轨道耦合（SOC），在 Rashba 和拓扑绝缘体（TI）表面态中发现了轨道纹理。在此，我们预测在 χ-硼烯手性单层的 /' 点处的线性色散狄拉克带中会出现 p/p 轨道纹理。通过将“第一性原理”计算与有效哈密顿量相结合，我们表明轨道赝自旋的方向与动量锁定，其方式与 TI 的自旋纹理类似。此外，考虑到层赝自旋自由度，这种晶格允许具有等效或相反手性的层堆叠。相应地，我们展示了通过设计的堆叠和外部电场对轨道纹理和层局域化的控制。例如，对于相反手性堆叠，电场允许对轨道纹理化的狄拉克锥进行开/关切换。
