Details
| Original language | English |
|---|---|
| Article number | L041404 |
| Journal | Physical Review B |
| Volume | 108 |
| Issue number | 4 |
| Publication status | Published - 20 Jul 2023 |
Abstract
The electron-hole exchange interaction is a fundamental mechanism that drives valley depolarization via intervalley exciton hopping in semiconductor multivalley systems. Here, we report polarization-resolved photoluminescence spectroscopy of neutral excitons and negatively charged trions in monolayer Formula Presented and Formula Presented under biaxial strain. We observe a marked enhancement (reduction) on the Formula Presented triplet trion valley polarization with compressive (tensile) strain while the trion in Formula Presented is unaffected. The origin of this effect is shown to be a strain-dependent tuning of the electron-hole exchange interaction. A combined analysis of the strain-dependent polarization degree using ab initio calculations and rate equations shows that strain affects intervalley scattering beyond what is expected from strain-dependent band-gap modulations. The results evidence how strain can be used to tune valley physics in energetically degenerate multivalley systems.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Physical Review B, Vol. 108, No. 4, L041404, 20.07.2023.
Research output: Contribution to journal › Letter › Research › peer review
}
TY - JOUR
T1 - Strain control of exciton and trion spin-valley dynamics in monolayer transition metal dichalcogenides
AU - An, Z.
AU - Soubelet, P.
AU - Zhumagulov, Y.
AU - Zopf, M.
AU - Delhomme, A.
AU - Qian, C.
AU - Faria Junior, P. E.
AU - Fabian, J.
AU - Cao, X.
AU - Yang, J.
AU - Stier, A. V.
AU - Ding, F.
AU - Finley, J. J.
N1 - Funding Information: We gratefully acknowledge the German Science Foundation (DFG) for financial support via SPP-2244 grants (DI 2013/5-1, FI 947/8-1, and FA 971/8-1). P.S., A.D., C.Q., A.V.S., and J.J.F. additionally acknowledge the clusters of excellence MCQST (EXS-2111) and e-conversion (EXS-2089). Z.A., M.Z., X.C., J.Y., and F.D. gratefully acknowledge the European Research Council (No. QD-NOMS GA715770), and the DFG Excellence Strategy-EXC-2123 Quantum Frontiers-39083 7967. Z.A. is funded by the China Scholarship Council. Y.Z., P.E.F.J., and J.F. also acknowledge the financial support of the DFG SFB 1277 (Project-ID 314695032, projects B07 and B11).
PY - 2023/7/20
Y1 - 2023/7/20
N2 - The electron-hole exchange interaction is a fundamental mechanism that drives valley depolarization via intervalley exciton hopping in semiconductor multivalley systems. Here, we report polarization-resolved photoluminescence spectroscopy of neutral excitons and negatively charged trions in monolayer Formula Presented and Formula Presented under biaxial strain. We observe a marked enhancement (reduction) on the Formula Presented triplet trion valley polarization with compressive (tensile) strain while the trion in Formula Presented is unaffected. The origin of this effect is shown to be a strain-dependent tuning of the electron-hole exchange interaction. A combined analysis of the strain-dependent polarization degree using ab initio calculations and rate equations shows that strain affects intervalley scattering beyond what is expected from strain-dependent band-gap modulations. The results evidence how strain can be used to tune valley physics in energetically degenerate multivalley systems.
AB - The electron-hole exchange interaction is a fundamental mechanism that drives valley depolarization via intervalley exciton hopping in semiconductor multivalley systems. Here, we report polarization-resolved photoluminescence spectroscopy of neutral excitons and negatively charged trions in monolayer Formula Presented and Formula Presented under biaxial strain. We observe a marked enhancement (reduction) on the Formula Presented triplet trion valley polarization with compressive (tensile) strain while the trion in Formula Presented is unaffected. The origin of this effect is shown to be a strain-dependent tuning of the electron-hole exchange interaction. A combined analysis of the strain-dependent polarization degree using ab initio calculations and rate equations shows that strain affects intervalley scattering beyond what is expected from strain-dependent band-gap modulations. The results evidence how strain can be used to tune valley physics in energetically degenerate multivalley systems.
UR - http://www.scopus.com/inward/record.url?scp=85165682507&partnerID=8YFLogxK
U2 - 10.48550/arXiv.2303.15325
DO - 10.48550/arXiv.2303.15325
M3 - Letter
AN - SCOPUS:85165682507
VL - 108
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 4
M1 - L041404
ER -