悬空债券
异质结
电子能带结构
密度泛函理论
电子结构
材料科学
极地的
表面状态
拓扑绝缘体
原子轨道
拓扑(电路)
凝聚态物理
化学物理
计算化学
电子
化学
曲面(拓扑)
光电子学
物理
几何学
硅
量子力学
组合数学
数学
作者
Ünal Özden Akkuş,Erdem Balcı,Savaş Berber
标识
DOI:10.1016/j.apsusc.2018.12.203
摘要
We have investigated the electronic structure of the Sc2C(OH)2 MXene interfacing with a polar AlN multi-layer or a hydrogenated AlN surface. Density functional theory calculations reveal that the nearly free electron (NFE) states of the MXene shift down when the MXene is in contact with a polar flat surface. The Sc2C(OH)2/AlN heterostructure shows a Dirac cone and inversion in the band structure. The H-s, Sc-d, and C-p orbitals are involved in the band-inversion. The electronic structure of Sc2C(OH)2/AlN heterostructure is found to be topological since the topological invariant Z2=1. We suggest that a band inversion can be induced by contacting with any flat insulating polar surface that has no excess surface-charge. However, it is crucial that the MXene surface is not perturbed (e.g., by dangling bonds). As a proof of concept, we have investigated the electronic structure of Sc2C(OH)2 adsorbed on a hydrogenated AlN surface and observed band inversion. The band dispersions of the adsorbed MXene are reminiscent of a Weyl semi-metal. The adsorption on a polar material is a facile method to induce a topological electronic structure in the Sc2C(OH)2 MXene, which may be utilized in various device applications.
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