Autoionization and Dressing of Excited Excitons by Free Carriers in Monolayer WSe2

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Koloman Wagner - , University of Regensburg (Author)
  • Edith Wietek - , University of Regensburg (Author)
  • Jonas D. Ziegler - , University of Regensburg (Author)
  • Marina A. Semina - , RAS - Ioffe Physico Technical Institute (Author)
  • Takashi Taniguchi - , National Institute for Materials Science Tsukuba (Author)
  • Kenji Watanabe - , National Institute for Materials Science Tsukuba (Author)
  • Jonas Zipfel - , University of Regensburg (Author)
  • Mikhail M. Glazov - , RAS - Ioffe Physico Technical Institute (Author)
  • Alexey Chernikov - , University of Regensburg (Author)

Abstract

We experimentally demonstrate dressing of the excited exciton states by a continuously tunable Fermi sea of free charge carriers in a monolayer semiconductor. It represents an unusual scenario of two-particle excitations of charged excitons previously inaccessible in conventional material systems. We identify excited state trions, accurately determine their binding energies in the zero-density limit for both electron- and hole-doped regimes, and observe emerging many-body phenomena at elevated doping. Combining experiment and theory we gain access to the intra-exciton coupling facilitated by the interaction with free charge carriers. We provide evidence for a process of autoionization for quasiparticles, a unique scattering pathway available for excited states in atomic systems. Finally, we demonstrate a complete transfer of the optical transition strength from the excited excitons to dressed Fermi-polaron states as well as the associated light emission from their nonequilibrium populations.

Details

Original languageEnglish
Article number267401
JournalPhysical review letters
Volume125
Issue number26
Publication statusPublished - 21 Dec 2020
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 33449708

Keywords

ASJC Scopus subject areas