论文标题
INA和INSB表面的电子结构：密度功能理论和角度分辨光发射光谱法
Electronic structure of InAs and InSb surfaces: density functional theory and angle-resolved photoemission spectroscopy
论文作者
论文摘要
表面的电子结构在量子设备的性质中起关键作用。但是，表面也是模拟和工程师最具挑战性的。在这里，我们使用密度功能理论（DFT）和角度分辨光发射光谱（ARPES）的组合研究了INAS（001），INAS（111）和INSB（110）表面的电子结构。我们能够通过使用机器学习的Hubbard U校正来执行大规模的第一原理模拟并捕获不同表面重建的效果[NPJ Comput。母校。 6，180（2020）]。为了促进与ARPES结果的直接比较，我们通过将超级细胞表面平板模型的计算出的带状结构投射到大量原始细胞上，实现了“批量展开”方案。对于所有三个表面，我们在DFT计算和ARPE之间找到了一个很好的一致性。对于INAS（001），模拟阐明了表面重建的效果。发现不同的重建会产生独特的表面状态。对于INAS（111）和INSB（110），模拟有助于阐明氧化的影响。由于从AS到O的电荷转移大于从SB到O的电荷转移，因此INAS的氧化（111）会导致显着的带弯曲并产生电子口袋，而INSB的氧化（110）则不会。我们组合的理论和实验结果可能会为基于INAS和INSB半导体的量子设备的设计提供信息，例如利用Majoraana零模式的拓扑量表。
The electronic structure of surfaces plays a key role in the properties of quantum devices. However, surfaces are also the most challenging to simulate and engineer. Here, we study the electronic structure of InAs(001), InAs(111), and InSb(110) surfaces using a combination of density functional theory (DFT) and angle-resolved photoemission spectroscopy (ARPES). We were able to perform large-scale first principles simulations and capture effects of different surface reconstructions by using DFT calculations with a machine-learned Hubbard U correction [npj Comput. Mater. 6, 180 (2020)]. To facilitate direct comparison with ARPES results, we implemented a "bulk unfolding" scheme by projecting the calculated band structure of a supercell surface slab model onto the bulk primitive cell. For all three surfaces, we find a good agreement between DFT calculations and ARPES. For InAs(001), the simulations clarify the effect of the surface reconstruction. Different reconstructions are found to produce distinctive surface states. For InAs(111) and InSb(110), the simulations help elucidate the effect of oxidation. Owing to larger charge transfer from As to O than from Sb to O, oxidation of InAs(111) leads to significant band bending and produces an electron pocket, whereas oxidation of InSb(110) does not. Our combined theoretical and experimental results may inform the design of quantum devices based on InAs and InSb semiconductors, e.g., topological qubits utilizing the Majorana zero modes.
