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 eadi1323

Graphene 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

PubMed

38324690

More information

Latest update

3/1/2024 1