論文 Motion of Two-Dimensional Excitons in Momentum Space Leads to Pseudospin Distribution Narrowing on the Bloch Sphere

Garima Gupta ; Kenji Watanabe SAMURAI ORCID (National Institute for Materials Science) ; Takashi Taniguchi SAMURAI ORCID (National Institute for Materials Science) ; Kausik Majumdar

コレクション

引用
Garima Gupta, Kenji Watanabe, Takashi Taniguchi, Kausik Majumdar. Motion of Two-Dimensional Excitons in Momentum Space Leads to Pseudospin Distribution Narrowing on the Bloch Sphere. Nano Letters. 2024, 24 (18), 5413-5419. https://doi.org/10.1021/acs.nanolett.3c04808

説明:

(abstract)

Motional narrowing implies narrowing induced by motion, for example, in nuclear resonance, the thermally induced random motion of the nuclei in an inhomogeneous environment leads to counter-intuitive narrowing of the resonance line. Similarly, the excitons in monolayer semiconductors experience magnetic inhomogeneity: the electron-hole spinexchange interaction manifests as an in-plane pseudo-magnetic field with a periodically varying orientation inside the exciton band. The excitons undergo random momentum scattering and pseudospin precession repeatedly in this inhomogeneous magnetic environment – typically resulting in fast exciton depolarization. On the contrary, we show that such magnetic inhomogeneity averages out at high scattering rate due to motional narrowing. Physically, a faster exciton scattering leads to a narrower pseudospin distribution on the Bloch sphere, implying a nontrivial improvement in exciton polarization. The in-plane nature of the pseudomagnetic field enforces a contrasting scattering dependence between the circularly and linearly polarized excitons – providing a spectroscopic way to gauge the sample quality.

権利情報:

  • In Copyright
    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © 2024 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.nanolett.3c04808.

キーワード: 2D materials, Exciton Pseudospin, Valley Decoherence, Motional Narrowing, Polarization Contrast, MoS2

刊行年月日: 2024-05-08

出版者: American Chemical Society (ACS)

掲載誌:

  • Nano Letters (ISSN: 15306984) vol. 24 issue. 18 p. 5413-5419

研究助成金:

  • Indian Space Research Organisation
  • Ministry of Education, Culture, Sports, Science and Technology
  • Science and Engineering Research Board
  • Japan Society for the Promotion of Science 21H05233
  • Japan Society for the Promotion of Science 23H02052
  • Karnataka Innovation and Technology Society

原稿種別: 著者最終稿 (Accepted manuscript)

MDR DOI:

公開URL: https://doi.org/10.1021/acs.nanolett.3c04808

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更新時刻: 2025-07-29 12:30:27 +0900

MDRでの公開時刻: 2025-07-29 12:21:26 +0900

ファイル名 サイズ
ファイル名 2024A00528G_Manuscript.pdf (サムネイル)
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ファイル名 2024A00528G_Supporting_Information.pdf
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ファイル名 2024A00528G_Supplementary_videos.zip
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