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Title: Magnetic-gateable valley exciton emission

The use of valley excitonic states of transition metal dichalcogenides to store and manipulate information is hampered by fast carrier recombination and short valley lifetime. We propose theoretically a scheme to overcome such an obstacle, by applying a tilted exchange field through the magnetic proximity effect on monolayer MoS2. While the in-plane component of the exchange field brightens the dark exciton by spin mixing, the out-of-plane field can effectively gate the emission with an ON/OFF ratio of 2700. Importantly, the brightening is valley selective, leading to nearly 100% valley and spin polarization at room temperature. The resulting strongly gateable dark-exciton emission with long lifetime and near unity valley polarization makes it convenient to manipulate the valley degree of freedom, which may offer new paradigm for information processing and transmission.

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Publication Date:
Journal Name:
npj Computational Materials
Nature Publishing Group
Sponsoring Org:
National Science Foundation
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