Assessing Nontrivial Topology in Weyl Semimetals by Dichroic Photoemission

J. Schusser, H. Bentmann, M. Ünzelmann, T. Figgemeier, C.-H. Min, S. Moser, J. N. Neu, T. Siegrist, and F. Reinert

Phys. Rev. Lett. 129, 246404 – Published 9 December 2022

Abstract

The electronic structure of Weyl semimetals features Berry flux monopoles in the bulk and Fermi arcs at the surface. While angle-resolved photoelectron spectroscopy (ARPES) is successfully used to map the bulk and surface bands, it remains a challenge to explicitly resolve and pinpoint these topological features. Here we combine state-of-the-art photoemission theory and experiments over a wide range of excitation energies for the Weyl semimetals TaAs and TaP. Our results show that simple surface-band-counting schemes, proposed previously to identify nonzero Chern numbers, are ambiguous due to pronounced momentum-dependent spectral weight variations and the pronounced surface-bulk hybridization. Instead, our findings indicate that dichroic ARPES provides an improved approach to identify Fermi arcs but requires an accurate description of the photoelectron final state.

Received 15 June 2022
Revised 26 August 2022
Accepted 21 November 2022
Corrected 19 April 2023

DOI:https://doi.org/10.1103/PhysRevLett.129.246404

Physics Subject Headings (PhySH)

Electronic structure Fermi surface Surface states Topological materials

Weyl semimetal

Angle-resolved photoemission spectroscopy Density functional theory Korringa-Kohn-Rostoker method Topology

Condensed Matter, Materials & Applied Physics

Corrections

19 April 2023

Correction: The omission of an acknowledgment statement has been fixed.

Authors & Affiliations

J. Schusser ^1,*, H. Bentmann¹, M. Ünzelmann¹, T. Figgemeier¹, C.-H. Min^2,3, S. Moser⁴, J. N. Neu^5,6, T. Siegrist^5,7, and F. Reinert ¹

¹Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074 Würzburg, Germany
²Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
³Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
⁴Experimentelle Physik IV and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074 Würzburg, Germany
⁵National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
⁶Nuclear Nonproliferation Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
⁷Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, Florida 32310, USA