Detecting and Correcting Piezoelectric-Tube Actuator Drift Induced Distortion in Atomic-Resolution Scanning Tunneling Microscope Images from Crystal Surfaces

Since its development in 1981, Scanning Tunneling Microscopy (STM) has become a premier technology in imaging at atomic resolution across disciplines. The “Scanning” in STM refers typically to the movement of the sample relative to the probing tip, as controlled by piezoelectric-tube actuators. These actuators allow the sample to be moved at sub-nanometer precision, but over several repeated scans are susceptible to drift, especially when operating in open-loop mode. This drift leads to directly detectable distortions in the image [1], which inevitably decrease the fidelity and by extension the science that can be done with the image. To make matters worse, as the process to correct or account for this drift can be complex, many publications simply forgo the exercise entirely, leading to some “untenable conclusions” [1] being drawn from compromised data