Isotropic Dirac fermion and anomalous oscillator strength of zeroth Landau level transition
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912768180879360 |
|---|---|
| author | Shi, Zeping Wu, Wenbin Wang, Guangyi Ozerov, Mykhaylo Yuan, Jian Xia, Wei Du, Yuhan Meng, Xianghao Jiang, Xiangyu Zhou, Mingsen Chen, Yuxi Shen, Hao Guo, Yanfeng Chu, Junhao Yuan, Xiang |
| author_facet | Shi, Zeping Wu, Wenbin Wang, Guangyi Ozerov, Mykhaylo Yuan, Jian Xia, Wei Du, Yuhan Meng, Xianghao Jiang, Xiangyu Zhou, Mingsen Chen, Yuxi Shen, Hao Guo, Yanfeng Chu, Junhao Yuan, Xiang |
| contents | Dirac fermions, characterized by their linear dispersion and relativistic nature, have emerged as a prominent class of quasiparticles in condensed matter physics. While the Dirac equation, initially developed in the context of high-energy physics, provides a remarkable framework for describing the electronic properties of these materials, the inherent symmetry constraints of condensed matter often lead to deviations from the idealized paradigm. In particular, three-dimensional Dirac fermions in solids often exhibit anisotropic behavior, challenging the notion of perfect symmetry inherent in the Dirac equation. Here, we report the observation of isotropic massive Dirac fermions in LaAlSi through Landau level spectroscopy. The presence of three-dimensional massive Dirac fermions across the Fermi energy is demonstrated by quantized and semiclassical analyses of the magnetic field evolution of Landau level transitions. The isotropic topological nature, Fermi velocity, and Dirac mass are evidenced by the identical magneto-infrared response among the Faraday and three Voigt geometries. Furthermore, we observe an unusually large oscillator strength in the zeroth Landau level transition of the Dirac fermion, compared to transitions with higher indices. This phenomenon, supported by model calculations, can be attributed to the combined effects of the partial excitation of Dirac fermion and the resonant dielectric coupling with the Weyl plasma. Our work provides a strategy for realizing ideal quasiparticle excitations and their coupling effects in condensed matter systems, offering a platform for exploring relativistic physics. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_14282 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Isotropic Dirac fermion and anomalous oscillator strength of zeroth Landau level transition Shi, Zeping Wu, Wenbin Wang, Guangyi Ozerov, Mykhaylo Yuan, Jian Xia, Wei Du, Yuhan Meng, Xianghao Jiang, Xiangyu Zhou, Mingsen Chen, Yuxi Shen, Hao Guo, Yanfeng Chu, Junhao Yuan, Xiang Materials Science Mesoscale and Nanoscale Physics Dirac fermions, characterized by their linear dispersion and relativistic nature, have emerged as a prominent class of quasiparticles in condensed matter physics. While the Dirac equation, initially developed in the context of high-energy physics, provides a remarkable framework for describing the electronic properties of these materials, the inherent symmetry constraints of condensed matter often lead to deviations from the idealized paradigm. In particular, three-dimensional Dirac fermions in solids often exhibit anisotropic behavior, challenging the notion of perfect symmetry inherent in the Dirac equation. Here, we report the observation of isotropic massive Dirac fermions in LaAlSi through Landau level spectroscopy. The presence of three-dimensional massive Dirac fermions across the Fermi energy is demonstrated by quantized and semiclassical analyses of the magnetic field evolution of Landau level transitions. The isotropic topological nature, Fermi velocity, and Dirac mass are evidenced by the identical magneto-infrared response among the Faraday and three Voigt geometries. Furthermore, we observe an unusually large oscillator strength in the zeroth Landau level transition of the Dirac fermion, compared to transitions with higher indices. This phenomenon, supported by model calculations, can be attributed to the combined effects of the partial excitation of Dirac fermion and the resonant dielectric coupling with the Weyl plasma. Our work provides a strategy for realizing ideal quasiparticle excitations and their coupling effects in condensed matter systems, offering a platform for exploring relativistic physics. |
| title | Isotropic Dirac fermion and anomalous oscillator strength of zeroth Landau level transition |
| topic | Materials Science Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2512.14282 |