Robust circular polarization of indirect Q-K transitions in bilayer 3R-W S2

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Tutkijat

  • Luojun Du

  • Qian Zhang
  • Tingting Zhang
  • Zhiyan Jia
  • Jing Liang
  • Gui Bin Liu
  • Rong Yang
  • Dongxia Shi
  • Jianyong Xiang
  • Kaihui Liu
  • Zhipei Sun

  • Yugui Yao
  • Qingming Zhang
  • Guangyu Zhang

Organisaatiot

  • Chinese Academy of Sciences
  • Renmin University of China
  • Beijing Institute of Technology
  • Yanshan University
  • Peking University
  • Lanzhou University
  • University of Chinese Academy of Sciences
  • Songshan Lake Materials Laboratory

Kuvaus

Valley-contrasting Berry curvature and orbital magnetic moment have led to highly selective circular polarization of direct excitons at the K valleys in transition-metal dichalcogenides. In addition to K valleys, Q valleys, another critical point in the conduction band, also possess well-defined but distinct magnetic moment. Being akin to the direct excitons at K valleys, indirect excitons associated with Q (K) valleys in the conduction (valence) band could allow circular polarization in principle. Here, we report an experimental observation of the circular polarization of indirect Q-K transitions in noncentrosymmetric bilayer 3R-WS2. In stark contrast to the circular polarization of direct excitons which depolarizes with increasing lattice temperature, the circular polarization of indirect Q-K excitons is extremely robust and independent on the temperature. Such robust circular polarization can be understood as follows: The spin-orbit coupling in the Q valley is much stronger than that in the K point of the conduction band, significantly suppressing the temperature induced valley depolarization. Our results open up opportunities for exotic valleytronics and quantum information processing applications.

Yksityiskohdat

AlkuperäiskieliEnglanti
Artikkeli161404
JulkaisuPhysical Review B
Vuosikerta100
Numero16
TilaJulkaistu - 23 lokakuuta 2019
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

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