Probing electron-hole Coulomb correlations in the exciton landscape of a twisted semiconductor heterostructure
Journal article, 2024
In two-dimensional semiconductors, cooperative and correlated interactions determine the material’s excitonic properties and can even lead to the creation of correlated states of matter. Here, we study the fundamental two-particle correlated exciton state formed by the Coulomb interaction between single-particle holes and electrons. We find that the ultrafast transfer of an exciton’s hole across a type II band-aligned semiconductor heterostructure leads to an unexpected sub-200-femtosecond upshift of the single-particle energy of the electron being photoemitted from the two-particle exciton state. While energy relaxation usually leads to an energetic downshift of the spectroscopic signature, we show that this upshift is a clear fingerprint of the correlated interaction of the electron and hole parts of the exciton. In this way, time-resolved photoelectron spectroscopy is straightforwardly established as a powerful method to access electron-hole correlations and cooperative behavior in quantum materials. Our work highlights this capability and motivates the future study of optically inaccessible correlated excitonic and electronic states of matter.
Author
Jan Philipp Bange
University of Göttingen
David Schmitt
University of Göttingen
Wiebke Bennecke
University of Göttingen
Giuseppe Meneghini
Philipps University Marburg
Abdul Aziz AlMutairi
Department of Engineering
Kenji Watanabe
National Institute for Materials Science (NIMS)
Takashi Taniguchi
National Institute for Materials Science (NIMS)
Daniel Steil
University of Göttingen
Sabine Steil
University of Göttingen
R. Thomas Weitz
University of Göttingen
G. S.Matthijs Jansen
University of Göttingen
Stephan Hofmann
Department of Engineering
Samuel Brem
Philipps University Marburg
Ermin Malic
Chalmers, Physics, Condensed Matter and Materials Theory
Philipps University Marburg
Marcel Reutzel
University of Göttingen
Stefan Mathias
University of Göttingen
Science advances
2375-2548 (eISSN)
Vol. 10 6 eadi1323Graphene Core Project 3 (Graphene Flagship)
European Commission (EC) (EC/H2020/881603), 2020-04-01 -- 2023-03-31.
Subject Categories
Atom and Molecular Physics and Optics
Condensed Matter Physics
DOI
10.1126/sciadv.adi1323