Electron dynamics in a three-dimensional Brillouin zone analysed by machine learning

Abstract

The electron dynamics in the unoccupied states of the Weyl semimetal PtBi${}_2$ is studied by time- and angle-resolved photoemission spectroscopy (TR-ARPES). The measurement's result is the photoemission intensity $I$ as a function of at least four parameters: the emission angle and kinetic energy of the photoelectrons, the time delay between pump and probe laser pulses, and the probe laser photon energy that needs to be varied to access the full three-dimensional Brillouin zone of the material. The TR-ARPES results are reported in an accompanying paper. Here we focus on the technique of using $k$-means, an unsupervised machine learning technique, in order to discover trends in the four-dimensional data sets. We study how to compare the electron dynamics across the entire data set and how to reveal subtle variations between different data sets collected in the vicinity of the bulk Weyl points.

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Cited by in corpus (3)

• Interplay between inversion and translation symmetries in trigonal PtBi${}_2$
• Clustering-Enhanced Time- and Angle-Resolved Photoemission Study of LaTe${}_3$: Absence of a Photoinduced Secondary CDW in the Electronic Structure
• Mesoscale variations of chemical and electronic landscape on the surface of Weyl semimetal Co${}_3$Sn${}_2$S${}_2$ visualized by ARPES and XPS