Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 73: Electronic Structure of Surfaces 1

O 73.9: Vortrag

Donnerstag, 8. September 2022, 17:00–17:15, S053

Theoretical and experimental HARPES study of Weyl-semimetal TaAs: The application of machine-learning — •Trung-Phuc Vo¹, Arian Arab², Sunil Wilfred D’Souza¹, Laurent Nicolaï¹, Tien-Lin Lee³, Nitesh Kumar⁴, Claudia Felser⁴, Alexander Gray², and Ján Minár¹ — ¹New Technologies - Research Centre, University of West Bohemia, 301 00 Pilsen, Czech Republic — ²Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA — ³Diamond Light Source Ltd., Didcot, Oxfordshire OX11 0DE, United Kingdom — ⁴Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany

The electronic structure properties of tantalum arsenide (TaAs), a Weyl semimetal, have been studied by soft and hard X-ray angle-resolved photoemission spectroscopy (ARPES) at energies of 440 eV and 2150 eV, respectively. For the first time, TaAs is experimentally investigated by the bulk sensitive photoemission in the hard X-ray regime. In order to interpret experimental data we performed one-step model of photoemission calculation which includes all matrix elements and final state effects. Due to the strong photon momentum effects and uncertainty in the tilt of experimental geometry we used a so-called machine learning algorithm combined with a free-electron final-state model to find best possible experimental parameters. Our findings re-emphasize the overwhelming accuracy of hard X-ray ARPES compared to the traditional ultraviolet and soft X-ray one in case of bulk electronic structure, motivating further material discoveries.