2024/12/07 by Richa Mishra, Mishra, Richa, S. O. Reza Moheimani +1
Physics and Astronomy · Engineering · #Advanced Chemical Physics Studies #Quantum and electron transport phenomena #Molecular Junctions and Nanostructures
paper · pdf · doi:10.48550/arxiv.2412.05729
We introduce a novel control mode for Scanning Tunneling Microscopy (STM) that leverages di/dz feedback. By superimposing a high-frequency sinusoidal modulation on the control signal, we extract the amplitude of the resulting tunneling current to obtain a di/dz measurement as the tip is scanned over the surface. A feedback control loop is then closed to maintain a constant di/dz, enhancing the sensitivity of the tip to subtle surface variations throughout a scan. This approach offers distinct advantages over conventional constant-current imaging. We demonstrate the effectiveness of this technique through high-resolution imaging and lithographic experiments on several Si(100)-2x1:H surfaces. Our findings, validated across multiple STM systems and imaging conditions, pave the way for a new paradigm in STM control, imaging, and lithography.