Momentum-Resolved Exciton Coupling and Valley Polarization Dynamics in Monolayer WS2

Alice Kunin; Sergey Chernov; Jin Bakalis; Ziling Li; Shuyu Cheng; Zachary H. Withers; Michael G. White; Gerd Schönhense; Xu Du; Roland K. Kawakami; Thomas K. Allison

doi:10.1103/PhysRevLett.130.046202

Momentum-Resolved Exciton Coupling and Valley Polarization Dynamics in Monolayer WS2

Alice Kunin, Sergey Chernov, Jin Bakalis, Ziling Li, Shuyu Cheng, Zachary H. Withers, Michael G. White, Gerd Schönhense, Xu Du, Roland K. Kawakami, Thomas K. Allison

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

19 Scopus citations

Abstract

Using time- and angle-resolved photoemission, we present momentum- and energy-resolved measurements of exciton coupling in monolayer WS2. We observe strong intravalley coupling between the B1s exciton and An>1 states. Our measurements indicate that the dominant valley depolarization mechanism conserves the exciton binding energy and momentum. While this conservation is consistent with Coulomb exchange-driven valley depolarization, we do not observe a momentum or energy dependence to the depolarization rate as would be expected for the exchange-based mechanism.

Original language	English (US)
Article number	046202
Journal	Physical review letters
Volume	130
Issue number	4
DOIs	https://doi.org/10.1103/PhysRevLett.130.046202
State	Published - Jan 27 2023
Externally published	Yes

All Science Journal Classification (ASJC) codes

General Physics and Astronomy

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10.1103/PhysRevLett.130.046202

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title = "Momentum-Resolved Exciton Coupling and Valley Polarization Dynamics in Monolayer WS2",

abstract = "Using time- and angle-resolved photoemission, we present momentum- and energy-resolved measurements of exciton coupling in monolayer WS2. We observe strong intravalley coupling between the B1s exciton and An>1 states. Our measurements indicate that the dominant valley depolarization mechanism conserves the exciton binding energy and momentum. While this conservation is consistent with Coulomb exchange-driven valley depolarization, we do not observe a momentum or energy dependence to the depolarization rate as would be expected for the exchange-based mechanism.",

author = "Alice Kunin and Sergey Chernov and Jin Bakalis and Ziling Li and Shuyu Cheng and Withers, {Zachary H.} and White, {Michael G.} and Gerd Sch{\"o}nhense and Xu Du and Kawakami, {Roland K.} and Allison, {Thomas K.}",

note = "Publisher Copyright: {\textcopyright} 2023 American Physical Society.",

year = "2023",

month = jan,

day = "27",

doi = "10.1103/PhysRevLett.130.046202",

language = "English (US)",

volume = "130",

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TY - JOUR

T1 - Momentum-Resolved Exciton Coupling and Valley Polarization Dynamics in Monolayer WS2

AU - Kunin, Alice

AU - Chernov, Sergey

AU - Bakalis, Jin

AU - Li, Ziling

AU - Cheng, Shuyu

AU - Withers, Zachary H.

AU - White, Michael G.

AU - Schönhense, Gerd

AU - Du, Xu

AU - Kawakami, Roland K.

AU - Allison, Thomas K.

PY - 2023/1/27

Y1 - 2023/1/27

N2 - Using time- and angle-resolved photoemission, we present momentum- and energy-resolved measurements of exciton coupling in monolayer WS2. We observe strong intravalley coupling between the B1s exciton and An>1 states. Our measurements indicate that the dominant valley depolarization mechanism conserves the exciton binding energy and momentum. While this conservation is consistent with Coulomb exchange-driven valley depolarization, we do not observe a momentum or energy dependence to the depolarization rate as would be expected for the exchange-based mechanism.

AB - Using time- and angle-resolved photoemission, we present momentum- and energy-resolved measurements of exciton coupling in monolayer WS2. We observe strong intravalley coupling between the B1s exciton and An>1 states. Our measurements indicate that the dominant valley depolarization mechanism conserves the exciton binding energy and momentum. While this conservation is consistent with Coulomb exchange-driven valley depolarization, we do not observe a momentum or energy dependence to the depolarization rate as would be expected for the exchange-based mechanism.

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DO - 10.1103/PhysRevLett.130.046202

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JO - Physical review letters

JF - Physical review letters

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ER -

Momentum-Resolved Exciton Coupling and Valley Polarization Dynamics in Monolayer WS2

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