Layer k-projection and unfolding electronic bands at interfaces
Layer k-projection and unfolding electronic bands at interfaces
复制标题
层 k 投影和界面处展开的电子带
DOI：
10.1103/physrevb.98.245421
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发表时间：
2018-12-26
影响因子：
3.7
通讯作者：
Weinert, M.
中科院分区：
文献类型：
--
作者：
Chen, Mingxing;Weinert, M.
k-投影法提供了一种分离异质结构系统中不同组分的贡献的方法，并且可以作为连接实验结果和计算结果的辅助手段。我们表明，该技术可用于“展开”界面和超级单元的计算电子带，并通过在特定空间区域上积分投影状态来提供局部带结构，这一步骤可以使用快速傅里叶变换有效地实现。我们应用该方法研究了由石墨烯双分子层（h -饱和SiC(0001)）、BAs单层（铁磁半导体CrI3）、硅烯（Ag(111)）和Bi2Se3表面组成的异质结构中界面的影响。我们的研究结果表明，Dirac点周围石墨烯双分子层的带结构强烈依赖于SiC（0001）的终止：在C面，石墨烯被n掺杂，并打开了一个类似于0.13 eV的间隙，而在Si面，石墨烯基本保持不变和中性。我们发现，对于BAs/CrI3，磁邻近效应可以有效地诱导BAs中高达约50 meV的自旋分裂。对于硅烯/Ag(111)，我们的计算再现了角度分辨光发射光谱结果，包括Ag（111）第一布里渊带边缘的线性色散带；虽然这些状态是由硅烯覆盖层和衬底之间的相互作用产生的，但我们证明它们不是狄拉克态。
The k-projection method provides an approach to separate the contributions from different constituents in heterostructure systems, and can act as an aid to connect the results of experiments and calculations. We show that the technique can be used to "unfold" the calculated electronic bands of interfaces and supercells, and provide local band structure by integrating the projected states over specified regions of space, a step that can be implemented efficiently using fast Fourier transforms. We apply the method to investigate the effects of interfaces in heterostructures consisting of a graphene bilayer on H-saturated SiC(0001), BAs monolayer on the ferromagnetic semiconductor CrI3, silicene on Ag(111), and to the Bi2Se3 surface. Our results reveal that the band structure of the graphene bilayer around the Dirac point is strongly dependent on the termination of SiC(0001): on the C face, the graphene is n doped and a gap of similar to 0.13 eV is opened, whereas on the Si face, the graphene is essential unchanged and neutral. We show that for BAs/CrI3, the magnetic proximity effect can effectively induce a spin splitting up to about 50 meV in BAs. For silicene/Ag(111), our calculations reproduce the angle-resolved photoemission spectroscopy results, including linearly dispersing bands at the edge of the first Brillouin zone of Ag(111); although these states result from the interaction between the silicene overlayer and the substrate, we demonstrate that they are not Dirac states.