Self-manifestation and universal correction of image distortion in scanning tunneling microscopy with spiral scan.

We demonstrate that severe distortions may occur but hard to identify in a standard line-by-line scanned scanning tunneling microscope image, deforming the atomic lattice into a completely different structure type and leading to a wrong interpretation of the data. We also show that a spiral scan image can reveal the details of the drifting by causing the atomic rows to bend with the curvatures being closely related to the extent and direction of the drifting. By straightening the curved atomic rows, the true atomic arrangement can thus be precisely recovered.