Improving the low-dose performance of aberration correction in single sideband ptychography

TL;DR

This paper enhances aberration correction in single sideband ptychography under low-dose conditions by confining phase unwrapping and selecting well-unwrapped sidebands, leading to improved noise robustness in electron microscopy.

Contribution

It introduces two novel strategies to improve aberration correction performance in low-dose ptychography, enhancing robustness against noise.

Findings

Significant noise tolerance improvement in aberration correction

Enhanced robustness of low-dose electron ptychography

Validated with both simulated and experimental datasets

Abstract

The single sideband (SSB) framework of analytical electron ptychography can account for the presence of residual geometrical aberrations induced by the probe-forming lens. However, the accuracy of this aberration correction method is highly sensitive to noise, in part due to the necessity of phase unwrapping. In this work, we thus propose two strategies to improve aberration correction performance in low-dose conditions: confining phase unwrapping within the sidebands and selecting only well-unwrapped sidebands for calculating aberration coefficients. These strategies are validated through SSB reconstructions of both simulated and experimental 4D-STEM datasets of monolayer tungsten diselenide (WSe2). A comparison of results demonstrates significant improvements in Poisson noise tolerance, making aberration correction more robust and reliable for low-dose imaging.