Analysis of STM images with pure and CO-functionalized tips: A first-principles and experimental study
Analysis of STM images with pure and CO-functionalized tips: A first-principles and experimental study
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DOI：
10.1103/physrevb.96.085415
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发表时间：
2017-08-09
影响因子：
3.7
通讯作者：
Paulsson, Magnus
中科院分区：
文献类型：
--
作者：
Gustafsson, Alexander;Okabayashi, Norio;Paulsson, Magnus
我们描述了计算扫描隧道显微镜 (STM) 图像的第一原理方法，并将结果与结合 STM 与原子力显微镜 (AFM) 的充分表征的实验进行比较。该理论基于具有局域基组的密度泛函理论，其中真空间隙中的波函数是通过使用实空间网格将局域基波函数传播到间隙中来计算的。恒定高度 STM 图像是使用 Bardeen 近似方法计算的，包括对倒易空间进行平均。我们考虑吸附在 Cu(111) 上的铜吸附原子和单个 CO 分子，并使用带有和不带有 CO 官能化的单原子铜尖端进行扫描。计算出的图像与最先进的实验一致，其中尖端顶点的原子结构由 AFM 确定。通过比较，可以进一步详细解释 STM 图像。
We describe a first-principles method to calculate scanning tunneling microscopy (STM) images, and compare the results to well-characterized experiments combining STM with atomic force microscopy (AFM). The theory is based on density functional theory with a localized basis set, where the wave functions in the vacuum gap are computed by propagating the localized-basis wave functions into the gap using a real-space grid. Constant-height STM images are computed using Bardeen's approximation method, including averaging over the reciprocal space. We consider copper adatoms and single CO molecules adsorbed on Cu(111), scanned with a single-atom copper tip with and without CO functionalization. The calculated images agree with state-of-the-art experiments, where the atomic structure of the tip apex is determined by AFM. The comparison further allows for detailed interpretation of the STM images.