Excitons in mesoscopically reconstructed moiré heterostructures

Author(s)
Shen Zhao, Zhijie Li, Xin Huang, Anna Rupp, Jonas Göser, Ilia A. Vovk, Stanislav Yu Kruchinin, Kenji Watanabe, Takashi Taniguchi, Ismail Bilgin, Anvar S. Baimuratov, Alexander Högele
Abstract

Moiré effects in vertical stacks of two-dimensional crystals give rise to new quantum materials with rich transport and optical phenomena that originate from modulations of atomic registries within moiré supercells. Due to finite elasticity, however, the superlattices can transform from moiré-type to periodically reconstructed patterns. Here we expand the notion of such nanoscale lattice reconstruction to the mesoscopic scale of laterally extended samples and demonstrate rich consequences in optical studies of excitons in MoSe2–WSe2 heterostructures with parallel and antiparallel alignments. Our results provide a unified perspective on moiré excitons in near-commensurate semiconductor heterostructures with small twist angles by identifying domains with exciton properties of distinct effective dimensionality, and establish mesoscopic reconstruction as a compelling feature of real samples and devices with inherent finite size effects and disorder. Generalized to stacks of other two-dimensional materials, this notion of mesoscale domain formation with emergent topological defects and percolation networks will instructively expand the understanding of fundamental electronic, optical and magnetic properties of van der Waals heterostructures.

Organisation(s)
Computational Materials Physics
External organisation(s)
Ludwig-Maximilians-Universität München, ITMO University, Nuance Communications Austria GmbH, National Institute for Materials Science, Munich Center for Quantum Science and Technology (MCQST)
Journal
Nature Nanotechnology
Volume
18
Pages
572–579
No. of pages
8
ISSN
1748-3387
DOI
https://doi.org/10.48550/arXiv.2202.11139
Publication date
03-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
103015 Condensed matter, 103018 Materials physics
ASJC Scopus subject areas
Bioengineering, Atomic and Molecular Physics, and Optics, Biomedical Engineering, General Materials Science, Condensed Matter Physics, Electrical and Electronic Engineering
Portal url
https://ucrisportal.univie.ac.at/en/publications/e91c2b4f-0ae2-4765-9a03-085c54c6da7a