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Philipp Michael Pelz

Publications and source records attributed to Philipp Michael Pelz.

2 recordsLinked to original sources

Scalable multicomponent spectral analysis for high-throughput data annotation

Orchestrating parametric fitting of multicomponent spectra at scale is an essential yet underappreciated task in high-throughput quantification of materials and chemical composition. To automate the annotation process for spectroscopic and diffraction data collected in counts of hundreds to thousands, we present a systematic approach compatible with high-performance computing infrastructures using the MapReduce model and task-based parallelization. We implement the approach in software and demonstrate linear computational scaling with respect to spectral components using multidimensional experimental materials characterization datasets from photoemission spectroscopy and powder electron diffraction as benchmarks. Our approach enables efficient generation of high-quality data annotation and online spectral analysis and is applicable to a variety of analytical techniques in materials science and chemistry as a building block for closed-loop experimental systems.

cond-mat.mtrl-sci↗

Low-dose cryo electron ptychography via non-convex Bayesian optimization

Electron ptychography has seen a recent surge of interest for phase sensitive imaging at atomic or near-atomic resolution. However, applications are so far mainly limited to radiation-hard samples because the required doses are too high for imaging biological samples at high resolution. We propose the use of non-convex, Bayesian optimization to overcome this problem and reduce the dose required for successful reconstruction by two orders of magnitude compared to previous experiments. We suggest to use this method for imaging single biological macromolecules at cryogenic temperatures and demonstrate 2D single-particle reconstructions from simulated data with a resolution of 7.9 Å$\,$ at a dose of 20 $e^- / Å^2$. When averaging over only 15 low-dose datasets, a resolution of 4 Å$\,$ is possible for large macromolecular complexes. With its independence from microscope transfer function, direct recovery of phase contrast and better scaling of signal-to-noise ratio, cryo-electron ptychography may become a promising alternative to Zernike phase-contrast microscopy.

physics.comp-ph↗