Theoretical simulation of noncontact AFM images of Si(111) √3×√3-Ag surface based on Fourier expansion method

Abstract

A Fourier expansion method is introduced to simulate the noncontact atomic force microscopy (NC-AFM) images in an efficient way, where three dimensional (3D) tip–surface interaction force distribution calculated by the first-principles density functional (LDA) calculations are fitted to an analytical function. As an example of application of this method, we adopt a Si(111) √3×√3 R30°-Ag surface. Force spectroscopies and 2D images for different tip height are presented.