The optical selection rules obeyed by two-dimensional materials with spin-valley coupling enable the selective excitation of carriers. We show that several members of the monolayer MA2Z4 (M=Mo and W;A=C, Si, and Ge; Z=N, P, and As) family are direct band-gap semiconductors with protected valley states and that circularly polarized infrared light can induce valley-selective interband transitions. Therefore, they are able to generate a close to 100% valley- and spin-polarized current under an in-plane bias and circularly polarized infrared light, which can be exploited to encode, process, and store information.
|Original language||English (US)|
|Journal||Physical Review B|
|State||Published - May 31 2022|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-02
Acknowledgements: The authors thank Xu Gao and Mingyan Chen for providing technical support. This work was supported by the National Natural Science Foundation of China (Grants No. NSFC12004142 and No. NSFC12174158), the China Postdoctoral Science Foundation (Grant No. 2020M1350), the Natural Science Funds for Colleges and Universities in Jiangsu Province (Grant No. 20KJB140017), and the Postdoctoral Research Funding Program of Jiangsu Province (Grant No. 2020Z131). The research reported in this publication was also supported by the Singapore Ministry of Education Academic Research Fund Tier 1 (Grant No. R265-000-691-114) and funding from King Abdullah University of Science and Technology.