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  • Letter
  • Open Access

Leaky exciton condensates in transition metal dichalcogenide moiré bilayers

Benjamin Remez1,* and Nigel R. Cooper1,2

  • 1T.C.M. Group, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
  • 2Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Italy

  • *br395@cam.ac.uk
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Phys. Rev. Research 4, L022042 – Published 24 May, 2022

DOI: https://doi.org/10.1103/PhysRevResearch.4.L022042

Abstract

We show that the “dark condensates” that arise when excitons form a Bose-Einstein condensate in a material with an indirect band gap are not completely dark to optical emission. Rather, such states are “leaky condensates” in which optical emission is facilitated by many-body interactions. We analyze the properties of these leaky condensates in the context of twisted bilayers of transition metal dichalcogenides, which host strongly interacting excitons and an indirect band gap. We show that this interaction-driven “leaky” emission dominates photoluminescence at low temperatures, with distinctive qualitative features. Finally, we propose that in these materials unique intervalley physics can lead to crystal symmetry-breaking excitonic ordering, with implications for optical processes.

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Outline

Information

Phys. Rev. Research 4, L022042– Published 24 May, 2022
  • Received 20 October 2021
  • Revised 18 March 2022
  • Accepted 22 March 2022
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