Above-Curie-temperature ultrafast terahertz emission and spin current generation in a 2D superlattice (Fe3GeTe2/CrSb)3
The increasing demand for denser information storage and faster data processing has fueled a keen interest in exploring spin currents up to terahertz (THz) frequencies. Emergent 2D intrinsic magnetic materials constitute a novel and highly controllable platform to access such femtosecond spin dynamics at atomic layer thickness. However, the function of 2D van der Waals magnets are limited by their Curie temperatures, which are usually low. Here, in a 2D superlattice (Fe<sub>3</sub>GeTe<sub>2</sub>/CrSb)<sub>3</sub>, we demonstrate ultrafast laser-induced spin current generation and THz radiation at room temperature, overcoming the challenge of the Curie temperature of Fe<sub>3</sub>GeTe<sub>2</sub> being only 206 K. In tandem with time-resolved magneto-optical Kerr effect measurements and first-principles calculations, we further elucidate the origin of the spin currents-a laser-enhanced proximity effect manifested as a laser-induced reduction of interlayer distance and enhanced electron exchange interactions, which causes transient spin polarization in the heterostructure. Our findings present an innovative, magnetic-element-free route for generating ultrafast spin currents within the 2D limit, underscoring the significant potential of laser THz emission spectroscopy in investigating laser-induced extraordinary spin dynamics.
Authors
- Faxian Xiu (ORCID: https://orcid.org/0000-0003-2860-0369)
- Xiaojun Wu (ORCID: https://orcid.org/0000-0001-8737-6286)
- Junwei Tong (ORCID: https://orcid.org/0000-0003-4670-9763)
- Ping Gong (ORCID: https://orcid.org/0000-0002-0363-6608)
- Peiyan Li (ORCID: https://orcid.org/0000-0002-8677-559X)
- Jimin Zhao (ORCID: https://orcid.org/0000-0001-5696-9556)
- Na Wu
- Shanshan Liu (ORCID: https://orcid.org/0009-0006-7123-4535)
- Jianan Liu (ORCID: https://orcid.org/0000-0002-2953-4562)
- Sheng Meng (ORCID: https://orcid.org/0000-0002-1553-1432)
- Yu Cheng (ORCID: https://orcid.org/0000-0003-4259-0822)
- Wei He (ORCID: https://orcid.org/0000-0002-0501-0553)
Institutions
- Zhejiang International Studies University (CN)
- Chinese Academy of Sciences (CN)
- Fudan University (CN)
- Physical Sciences (United States) (US)
- Shanghai Zhangjiang Laboratory (CN)
- Songshan Lake Materials Laboratory (CN)
- FZU ‒ Institute of Physics of the Academy of Sciences of the Czech Republic (CZ)
- Wuhan National Laboratory for Optoelectronics (CN)
- Institute of Physics (CN)
- University of Chinese Academy of Sciences (CN)
- State Key Laboratory of Surface Physics
- Huazhong University of Science and Technology (CN)
- Freie Universität Berlin (DE)
- Beihang University (CN)
Publication Details
- Journal
- National Science Review
- Published
- 2024-12-11
- DOI
- https://doi.org/10.1093/nsr/nwae447
- Citations
- 4
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.47
Funders
- National Natural Science Foundation of China
- Fudan University
- Wuhan National Laboratory for Optoelectronics
- National Key Research and Development Program of China
- Center for Advanced Study, University of Illinois at Urbana-Champaign