Real-Time Atomic-Resolution Electron Phase Imaging without Probe Calibration via Ptychography-Supervised Learning
Authors: H. Yue, C. -C. Chen, C. -N. Hsiao, J. Cheng, Y. Liu, X. Z. Liao, Steve F. Shu
Organizations: College of Intelligent Robotics and Advanced Manufacturing, Fudan University, Shanghai 200433, China. · Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300044, Taiwan · National Center for Instrumentation Research, National Institutes of Applied Research, Hsinchu 300092, Taiwan · Institute for Infocomm Research, A*STAR, Singapore, 138632, Singapore · School of Aerospace, Mechanical and Mechatronic Engineering, and Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia. · School of Electrical and Computer Engineering, The University of Sydney, Sydney, NSW 2006, Australia
Atomic-scale phase imaging is central to resolving defects, interfaces, and weakly scattering atoms that govern the behavior of nanoscale materials. Electron ptychography delivers sub-ångström phase sensitivity but remains an offline technique, because its iterative reconstruction is computationally expensive and sensitive to experimental calibration, preventing live use during data acquisition. Here, a ptychography-supervised local inference framework is presented that converts four-dimensional scanning transmission electron microscopy (4D-STEM) into an acquisition-compatible phase-imaging workflow. Physics-constrained reference phase maps reconstructed from a single experimental AuPd dataset serve as teacher labels for a compact model that predicts local phase patches directly from diffraction measurements, without explicit probe input or online iterative optimization. Full-field images are assembled by deterministic overlap stitching. The workflow reaches an online latency of about 0.27 ms per probe position and a throughput of about 20,000 positions per second, an approximately 1,000-fold speed-up over GPU-accelerated ePIE, while preserving atomic-scale lattice contrast and reciprocal-space fidelity. Without fine-tuning, the same model transfers across materials (WS2), defocus conditions (high-entropy alloy nanoparticles), and instruments (hBN at 300 kV). The approach amortizes ptychographic redundancy into a fast, generalizable workflow that enables real-time atomic-scale phase imaging for materials microscopy.
Institute of Computational Intelligence, College of Artificial Intelligence, National Yang Ming Chiao Tung University, Taiwan · National Center for High-performance Computing, National Institutes of Applied Research, Taiwan