About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Journal of Physics C: Solid State Physics
Paper
Current distribution in the scanning vacuum tunnel microscope: A free-electron model
Abstract
Insight into the resolution of the recently developed technique of scanning tunnelling microscopy (STM) is achieved by considering the transmission of free electrons through a constant potential barrier with corrugated boundaries representing the sampled surface and probing tip, respectively. The amplitudes of the reflected and transmitted waves are calculated via an extension of the so-called GR-method developed to treat scattering from a corrugated hard wall. Results for the distribution of current density, for the dependence of the tunnelling current on the horizontal and vertical positions of the scanning tip and for the resulting equicurrent lines (STM images) are presented for a two-dimensional model. Simple analytical approximations are shown to reproduce computed trends versus tip-sample separation, tip curvature and average barrier height.