Types of STM images

For a given bias, the basic physical quantity measured by the STM is the tunneling current, which is a function of x = (x, y) and z  

If z is perpendicular to a nearly perfect surface, the tunneling current can be decomposed into a constant (that is, independent of x), and a small variable component that represents the features, or corrugation of the surface. 

By taking the current 1 as the variable v, a constant z current image is defined. Sometimes, for convenience, the relative variation of the tunneling current is taken as the image variable  

The constant-current topographic image can be derived from the current images as follows. Making an Ansatz, 

Due to the smallness of A/, the variation of the second term in Eq. (5.2) is neglected. The topographic image is then defined by the condition of constant current  

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Tunneling spectrum 24 Types of STM images 121, 122 current 121 topographic 122 Uncertainty principle 31, 64, 298 s-wave-tip model, and 31 scanning tunneling spectroscopy, and 197, 298... 

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