Formation of moiré interlayer excitons in space and time
Artikel i vetenskaplig tidskrift, 2022

Moiré superlattices in atomically thin van der Waals heterostructures hold great promise for extended control of electronic and valleytronic lifetimes1-7, the confinement of excitons in artificial moiré lattices8-13 and the formation of exotic quantum phases14-18. Such moiré-induced emergent phenomena are particularly strong for interlayer excitons, where the hole and the electron are localized in different layers of the heterostructure19,20. To exploit the full potential of correlated moiré and exciton physics, a thorough understanding of the ultrafast interlayer exciton formation process and the real-space wavefunction confinement is indispensable. Here we show that femtosecond photoemission momentum microscopy provides quantitative access to these key properties of the moiré interlayer excitons. First, we elucidate that interlayer excitons are dominantly formed through femtosecond exciton-phonon scattering and subsequent charge transfer at the interlayer-hybridized Σ valleys. Second, we show that interlayer excitons exhibit a momentum fingerprint that is a direct hallmark of the superlattice moiré modification. Third, we reconstruct the wavefunction distribution of the electronic part of the exciton and compare the size with the real-space moiré superlattice. Our work provides direct access to interlayer exciton formation dynamics in space and time and reveals opportunities to study correlated moiré and exciton physics for the future realization of exotic quantum phases of matter.

Författare

David Schmitt

Georg-August-Universität Göttingen

Jan Philipp Bange

Georg-August-Universität Göttingen

Wiebke Bennecke

Georg-August-Universität Göttingen

Abdul Aziz AlMutairi

Department of Engineering

Giuseppe Meneghini

Philipps-Universität Marburg

Kenji Watanabe

National Institute for Materials Science (NIMS)

Takashi Taniguchi

National Institute for Materials Science (NIMS)

Daniel Steil

Georg-August-Universität Göttingen

D. Russell Luke

Georg-August-Universität Göttingen

R. Thomas Weitz

Georg-August-Universität Göttingen

Sabine Steil

Georg-August-Universität Göttingen

G. S.Matthijs Jansen

Georg-August-Universität Göttingen

Samuel Brem

Philipps-Universität Marburg

Ermin Malic

Philipps-Universität Marburg

2D-Tech

Chalmers, Fysik, Kondenserad materie- och materialteori

Stephan Hofmann

Department of Engineering

Marcel Reutzel

Georg-August-Universität Göttingen

Stefan Mathias

Georg-August-Universität Göttingen

Nature

0028-0836 (ISSN) 1476-4687 (eISSN)

Vol. 608 7923 499-503

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Den kondenserade materiens fysik

DOI

10.1038/s41586-022-04977-7

PubMed

35978130

Mer information

Senast uppdaterat

2022-10-10