Comparison Between Several Control Techniques For Tunneling Current Regulation

This paper is about feedback control system for Scanning Tunneling Microscopy (STM). The system aims to maintain a constant tunneling current between tip and sample surface, despite external disturbances. Four controllers are tested and compared, resuming three previously considered techniques, and including a novel genetic-algorithm-based approach. Results in particular highlight the effectiveness of the latter in maintaining stability and rejecting disturbances, and the study includes both simulation and experimental results. The findings hence contribute to the development of reliable control systems for nanoscale imaging and manipulation.