2024/12/29 by Desheng Ma, Ma, Desheng, Steven E. Zeltmann +15
Biochemistry, Genetics and Molecular Biology · Materials Science · #Accelerator Physics (physics.acc-ph) #Advanced Electron Microscopy Techniques and Applications #Advanced Fluorescence Microscopy Techniques #Electron and X-Ray Spectroscopy Techniques #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.2412.20356
openalex publication_date 2024/12/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Aberration-corrected Scanning Transmission Electron Microscopy (STEM) has become an essential tool in understanding materials at the atomic scale. However, tuning the aberration corrector to produce a sub-Ångström probe is a complex and time-costly procedure, largely due to the difficulty of precisely measuring the optical state of the system. When measurements are both costly and noisy, Bayesian methods provide rapid and efficient optimization. To this end, we develop a Bayesian approach to fully automate the process by minimizing a new quality metric, beam emittance, which is shown to be equivalent to performing aberration correction. In part I, we derived several important properties of the beam emittance metric and trained a deep neural network to predict beam emittance growth from a single Ronchigram. Here we use this as the black box function for Bayesian Optimization and demonstrate automated tuning of simulated and real electron microscopes. We explore different surrogate functions for the Bayesian optimizer and implement a deep neural network kernel to effectively learn the interactions between different control channels without the need to explicitly measure a full set of aberration coefficients. Both simulation and experimental results show the proposed method outperforms conventional approaches by achieving a better optical state with a higher convergence rate.