Simultaneous High-Speed and Low-Dose 4-D STEM Using Compressive Sensing Techniques

TL;DR

This paper demonstrates that compressive sensing enables high-speed, low-dose 4-D STEM imaging by acquiring only a random subset of probe locations, maintaining accuracy and reducing data collection time.

Contribution

The study introduces a compressive sensing approach for 4-D STEM that significantly improves speed and reduces dose without sacrificing data quality, using random sampling of probe locations.

Findings

Achieved accurate 4-D STEM reconstruction with only 0.3% of data.

Recovered over 25dB peak SNR in phase from minimal data.

Detector downsampling does not compromise precision.

Abstract

Here we show that compressive sensing allow 4-dimensional (4-D) STEM data to be obtained and accurately reconstructed with both high-speed and low fluence. The methodology needed to achieve these results compared to conventional 4-D approaches requires only that a random subset of probe locations is acquired from the typical regular scanning grid, which immediately generates both higher speed and the lower fluence experimentally. We also consider downsampling of the detector, showing that oversampling is inherent within convergent beam electron diffraction (CBED) patterns, and that detector downsampling does not reduce precision but allows faster experimental data acquisition. Analysis of an experimental atomic resolution yttrium silicide data-set shows that it is possible to recover over 25dB peak signal-to-noise in the recovered phase using 0.3% of the total data.