Manipulating the valley degree of freedom of transition metal dichalcogenides via van der Waals magnetic tunnel junctions

ORAL

Abstract

The monolayer transition metal dichalcogenides (TMDs) are ideal candidates for future valleytronics applications owing to the unique spin valley locking properties and valley-dependent optical selection rule. Over the past few years, several works have shown the possibility of manipulating the valley degree of freedom of TMDs using circularly polarized light. But to electrically control the valley-dependent polarization remains a critical challenge. In this talk, we demonstrate that Fe3GeTe2 (FGT)-based tunneling contact can effectively inject spin-polarized holes into the specific valley of monolayer TMD. This importantly gives rise to valley-dependent polarization as confirmed by our helicity-dependent electroluminescence and reflective magnetic circular dichroism (RMCD) measurements. Moreover, our density functional theory calculations reveal that FGT owns the strong exchange splitting of spin bands at point K in its Brillouin zone, which enables the efficient injection of spin-polarized carriers. Our results not only provide further insight into FGT, but also address challenges of valleytronics.

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Publication: https://www.nature.com/articles/s41565-022-01115-2

Presenters

  • Jia-Xin Li

    • Institute of Photonics Technologies, National Tsing Hua University, Taiwan 30013, R.O.C.
    • Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan

Authors

  • Jia-Xin Li

    • Institute of Photonics Technologies, National Tsing Hua University, Taiwan 30013, R.O.C.
    • Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Wei-Qing Li

    • Institute of Photonics Technologies, National Tsing Hua University, Taiwan 30013, R.O.C.
    • Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan
    • National Tsing Hua University

  • Sheng-Hsiung Hung

    • Department of Physics, National Tsing Hua University, Hsinchu, 30013, Taiwan
    • National Tsing Hua University

  • Po-Liang Chen

    • Natl Tsing Hua University
    • Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Tian-Yun Chang

    • Institute of Photonics Technologies, National Tsing Hua University, Taiwan 30013, R.O.C.
    • Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Horng-Tay Jeng

    • National Tsing Hua University
    • Department of Physics, National Tsing Hua University, Hsinchu, 30013, Taiwan

  • Chang-Hua Liu

    • Institute of Photonics Technologies, National Tsing Hua University, Taiwan 30013, R.O.C.
    • Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan