Abstract
Theories have revealed the universality of the band tilting effect in topological Weyl semimetals (WSMs) and its implications for the material physical properties. However, the experimental identification of tilted Weyl bands remains less explored. Here, we report the magneto-optical evidence of the tilting effect in WSM niobium phosphide. Specifically, we observe Landau level transitions with rich features that are well reproduced within a model of coupled tilted Weyl points. Our analysis indicates that the tilting effect relaxes the selection rules and leads to transitions that would otherwise be forbidden in the non-tilt case. Additionally, we observe unconventional interband transitions with flat and negative magnetic field dispersions, highlighting the importance of coupling between Weyl points. Our results not only emphasize the significance of the tilting effect in the optical responses of WSMs but also demonstrate magneto-optics as an effective tool for probing the tilting effect in electronic band structures.
| Original language | English |
|---|---|
| Pages (from-to) | 2858-2863 |
| Number of pages | 6 |
| Journal | Nano Letters |
| Volume | 25 |
| Issue number | 7 |
| DOIs | |
| State | Published - Feb 19 2025 |
Funding
This work was primarily supported by the Department of Energy (Grant No. DE-FG02-07ER46451). Y.J. acknowledges support from the National Natural Science Foundation of China (Grant No. 12274001), the Natural Science Foundation of Anhui Province (Grant No. 2208085MA09), and the Department of Education of Anhui Province (Grant No. 2023AH020004). J.N. and T.S. acknowledge support by the National Science Foundation (Grant No. DMR-1606952). The magneto-IR measurements were performed at the National High Magnetic Field Laboratory, which is supported by the National Science Foundation Cooperative Agreement (Grant No. DMR-2128556) and the State of Florida.
Keywords
- Band structure
- Magneto-optics
- Tilting effect
- Weyl semimetal