Controllable orbital angular momentum monopoles in chiral topological semimetals
The emerging field of orbitronics aims to generate and control orbital angular momentum for information processing. Chiral crystals are promising orbitronic materials because they have been predicted to host monopole-like orbital textures, where the orbital angular momentum aligns isotropically with the electron's crystal momentum. However, such monopoles have not yet been directly observed in chiral crystals. Here, we use circular dichroism in angle-resolved photoelectron spectroscopy to image orbital angular momentum monopoles in the chiral topological semimetals PtGa and PdGa. The spectra show a robust polar texture that rotates around the monopole as a function of photon energy. This is a direct consequence of the underlying magnetic orbital texture and can be understood from the interference of local atomic contributions. Moreover, we also demonstrate that the polarity of the monopoles can be controlled through the structural handedness of the host crystal by imaging orbital angular moment monopoles and antimonopoles in the two enantiomers of PdGa, respectively. Our results highlight the potential of chiral crystals for orbitronic device applications, and our methodology could enable the discovery of even more complicated nodal orbital angular momentum textures that could be exploited for orbitronics.
Authors
- Maia G. Vergniory (ORCID: https://orcid.org/0000-0001-7336-3062)
- Vladimir N. Strocov (ORCID: https://orcid.org/0000-0002-1147-8486)
- Horst Borrmann (ORCID: https://orcid.org/0000-0002-1397-3261)
- Yun Yen (ORCID: https://orcid.org/0000-0003-1290-7390)
- M. Yao (ORCID: https://orcid.org/0000-0002-7487-1314)
- Iñigo Robredo (ORCID: https://orcid.org/0000-0003-1641-354X)
- S. Parkin (ORCID: https://orcid.org/0000-0003-4702-6139)
- Oliver Gröning
- Michael Schüler (ORCID: https://orcid.org/0000-0001-7322-6367)
- Niels B. M. Schröter (ORCID: https://orcid.org/0000-0001-6159-4576)
- Chandra Shekhar (ORCID: https://orcid.org/0000-0002-3330-0400)
- Kaustuv Manna (ORCID: https://orcid.org/0000-0002-9442-2321)
- Emily C. McFarlane (ORCID: https://orcid.org/0000-0002-9863-0187)
- Samuel Stolz (ORCID: https://orcid.org/0000-0002-3597-680X)
- Roland Widmer (ORCID: https://orcid.org/0000-0002-9226-3136)
- Claudia Felser (ORCID: https://orcid.org/0000-0002-8200-2063)
- Jonas A. Krieger (ORCID: https://orcid.org/0000-0003-3337-5530)
- Qun Yang (ORCID: https://orcid.org/0009-0002-9248-2555)
Institutions
- Université de Sherbrooke (CA)
- University of Fribourg (CH)
- Paul Scherrer Institute (CH)
- Max Planck Institute of Microstructure Physics (DE)
- Max Planck Institute for Chemical Physics of Solids (DE)
- Donostia International Physics Center (ES)
- École Polytechnique Fédérale de Lausanne (CH)
- Indian Institute of Technology Delhi (IN)
- Swiss Federal Laboratories for Materials Science and Technology (CH)
Publication Details
- Journal
- Nature Physics
- Published
- 2024-09-30
- DOI
- https://doi.org/10.1038/s41567-024-02655-1
- Citations
- 20
- Primary Topic
- Metamaterials and Metasurfaces Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.36
Funders
- National Science Foundation
- Ministerio de Ciencia, Innovación y Universidades
- European Commission
- Department of Atomic Energy, Government of India
- Deutsche Forschungsgemeinschaft
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Canada Excellence Research Chairs, Government of Canada
- Max-Planck-Gesellschaft
- Board of Research in Nuclear Sciences