A theoretical model of scanning tunneling microscopy: Application to the graphite (0001) and Au(111) surfaces
A theoretical model of scanning tunneling microscopy: Application to the graphite (0001) and Au(111) surfaces
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扫描隧道显微镜的理论模型：在石墨（0001）和Au（111）表面的应用
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
R. Marcus
中科院分区：
文献类型：
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作者：
Ou;B. Källebring;R. Marcus
使用一阶微扰理论的两个哈密顿形式主义（“反应物”和“产品”）之间的尖端和样品的扫描隧道显微镜（STM）电流的表达式。所计算的STM电流取决于在波矢量空间中的随机点的选择上平均的样品尖端矩阵元素的平方。在低电压和温度的限制下，这种平均是在样品的费米表面上。该模型被应用到石墨（0001）和Au（111）表面使用一个简单的模型（链）的钨尖和紧束缚近似。与实验和Tersoff和Lang使用钼尖获得的石墨的结果进行了比较。该理论适用于其他地方的吸附STM。
An expression for the scanning tunneling microscopy (STM) current between the tip and sample is presented using first-order perturbation theory for a two-Hamiltonian formalism ("reactants" and "products"). The calculated STM current depends on the square of the sample-tip matrix elements, averaged over a selection of random points in wave vector space. In the limit of low voltage and temperature, this averaging is over the Fermi surface of the sample. The model is applied to the graphite (0001) and Au(111) surfaces using a simple model (chain) of a tungsten tip and the tight-binding approximation. Comparisons with experiments and with the result for graphite obtained by Tersoff and Lang using a molybdenum tip are given. The theory is applied elsewhere to STM of adsorbates.