Magnetic-gateable valley exciton emission

Helena Bragança; Hao Zeng; Alexandre Cavalheiro Dias; Jorge Huamani Correa; Fanyao Qu

doi:10.1038/s41524-020-00356-w

Magnetic-gateable valley exciton emission

Helena Bragança
, Hao Zeng
, Alexandre Cavalheiro Dias
, Jorge Huamani Correa
, Fanyao Qu

Physics

Universidade de Brasília
Universidade Federal de Ouro Preto

Research output: Contribution to journal › Article › peer-review

11 Scopus citations

Abstract

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.

Original language	English
Article number	90
Journal	npj Computational Materials
Volume	6
Issue number	1
DOIs	https://doi.org/10.1038/s41524-020-00356-w
State	Published - Dec 1 2020

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title = "Magnetic-gateable valley exciton emission",

abstract = "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.",

author = "Helena Bragan{\c c}a and Hao Zeng and Dias, \{Alexandre Cavalheiro\} and Correa, \{Jorge Huamani\} and Fanyao Qu",

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T1 - Magnetic-gateable valley exciton emission

AU - Bragança, Helena

AU - Zeng, Hao

AU - Dias, Alexandre Cavalheiro

AU - Correa, Jorge Huamani

AU - Qu, Fanyao

PY - 2020/12/1

Y1 - 2020/12/1

N2 - 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.

AB - 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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DO - 10.1038/s41524-020-00356-w

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SN - 2057-3960

VL - 6

JO - npj Computational Materials

JF - npj Computational Materials

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ER -

Magnetic-gateable valley exciton emission

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