Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films
Abstract
Interplay of magnetism and electronic band topology in unconventional magnets enables the creation and fine control of novel electronic phenomena. In this work, we use scanning tunneling microscopy and spectroscopy to study thin films of a prototypical kagome magnet Fe3Sn2. Our experiments reveal an unusually large number of densely-spaced spectroscopic features straddling the Fermi level. These are consistent with signatures of low-energy Weyl fermions and associated topological Fermi arc surface states predicted by theory. By measuring their response as a function of magnetic field, we discover a pronounced evolution in energy tied to the magnetization direction. Electron scattering and interference imaging further demonstrates the tunable nature of a subset of related electronic states. Our experiments provide a direct visualization of how in-situ spin reorientation drives changes in the electronic density of states of the Weyl fermion band structure. Combined with previous reports of massive Dirac fermions, flat bands, and electronic nematicity, our work establishes Fe3Sn2 as an interesting platform that harbors an extraordinarily wide array of topological and correlated electron phenomena.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 15, 2022
- Source ID
- 10.1038/s41535-022-00521-y
Entities
People
- Bryan Rachmilowitz
- Dipak Bhattarai
- Faranak Bahrami
- Fazel Tafti
- He Zhao
- Hong Li
- Ilija Zeljkovic
- Madhav Prasad Ghimire
- Shiang Fang
- Shrinkhala Sharma
- Zheng Ren
- Ziqiang Wang
Organizations
- Army Research Office
- National Science Foundation