Yengui Mayssa, Pinto Henry P, Leszczynski Jerzy, Riedel Damien
Institut des Sciences Moléculaires d'Orsay, ISMO, UMR 8214, CNRS, Université Paris Sud, 91405 Orsay Cedex, France.
J Phys Condens Matter. 2015 Feb 4;27(4):045001. doi: 10.1088/0953-8984/27/4/045001. Epub 2014 Dec 19.
In this article, we study the origin of the corrugating and anticorrugating states through the electronic properties of the Si(1 0 0) surface via a low-temperature (9 K) scanning tunneling microscope (STM). Our study is based on the analysis of the STM topographies corrugation variations when related to the shift of the local density of states (LDOS) maximum in the [Formula: see text] direction. Our experimental results are correlated with numerical simulations using the density-functional theory with hybrid Heyd-Scuseria-Ernzerhof (HSE06) functional to simulate the STM topographies, the projected density of states variations at different depths in the silicon surface as well as the three dimensional partial charge density distributions in real-space. This work reveals that the Si(1 0 0) surface exhibits two anticorrugating states at +0.8 and +2.8 V that are associated with a phase shift of the LDOS maximum in the unoccupied states STM topographies. By comparing the calculated data with our experimental results, we have been able to identify the link between the variations of the STM topographies corrugation and the shift of the LDOS maximum observed experimentally. Each surface voltage at which the STM topographies corrugation drops is defined as anticorrugating states. In addition, we have evidenced a sharp jump in the tunnel current when the second LDOS maximum shift is probed, whose origin is discussed and associated with the presence of Van Hove singularities.
在本文中，我们通过低温（9 K）扫描隧道显微镜（STM），利用Si(1 0 0)表面的电子特性研究了波纹态和反波纹态的起源。我们的研究基于对STM形貌波纹变化的分析，这些变化与[公式：见原文]方向上局域态密度（LDOS）最大值的移动有关。我们的实验结果与使用杂化海-斯-厄（Heyd-Scuseria-Ernzerhof，HSE06）泛函的密度泛函理论进行的数值模拟相关，以模拟STM形貌、硅表面不同深度处的投影态密度变化以及实空间中的三维部分电荷密度分布。这项工作表明，Si(1 0 0)表面在+0.8 V和+2.8 V处表现出两个反波纹态，它们与未占据态STM形貌中LDOS最大值的相移有关。通过将计算数据与我们的实验结果进行比较，我们能够确定STM形貌波纹变化与实验观察到的LDOS最大值移动之间的联系。STM形貌波纹下降的每个表面电压都被定义为反波纹态。此外，当探测到第二个LDOS最大值移动时，我们证明了隧道电流的急剧跃升，其起源进行了讨论，并与范霍夫奇点的存在相关。
