1
|
Murotani Y, Kanda N, Fujimoto T, Matsuda T, Goyal M, Yoshinobu J, Kobayashi Y, Oka T, Stemmer S, Matsunaga R. Anomalous Hall Transport by Optically Injected Isospin Degree of Freedom in Dirac Semimetal Thin Film. NANO LETTERS 2024; 24:222-228. [PMID: 38147363 DOI: 10.1021/acs.nanolett.3c03770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Chirality of massless fermions emerging in condensed matter is a key to understand their characteristic behavior as well as to exploit their functionality. However, the chiral nature of massless fermions in Dirac semimetals has remained elusive, due to equivalent occupation of carriers with the opposite chirality in thermal equilibrium. Here, we show that the isospin degree of freedom, which labels the chirality of massless carriers from a crystallographic point of view, can be injected by circularly polarized light. Terahertz Faraday rotation spectroscopy successfully detects the anomalous Hall conductivity by a light-induced isospin polarization in a three-dimensional Dirac semimetal, Cd3As2. Spectral analysis of the Hall conductivity reveals a long scattering time and a long decay time, which are characteristic of the isospin. The long-lived, robust, and reversible character of the isospin promises a potential application of Dirac semimetals in future information technology.
Collapse
Affiliation(s)
- Yuta Murotani
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Natsuki Kanda
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Tomohiro Fujimoto
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Takuya Matsuda
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Manik Goyal
- Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| | - Jun Yoshinobu
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Yohei Kobayashi
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Takashi Oka
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| | - Ryusuke Matsunaga
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| |
Collapse
|