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Updated: Dec 21, 2025

Fabricating van der Waals Heterostructures with Precise Rotational Alignment
Published on: July 5, 2019
Twist-angle-dependent interlayer exciton diffusion in WS2-WSe2 heterobilayers.
Long Yuan1, Biyuan Zheng2, Jens Kunstmann3
1Department of Chemistry, Purdue University, West Lafayette, IN, USA.
Exciton motion in moiré superlattices is influenced by twist-angle-dependent potentials and interactions. This study reveals how these factors control exciton dynamics in van der Waals heterostructures for quantum devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Moiré patterns in van der Waals heterostructures create nanoscale potentials for exciton superlattices.
- Understanding exciton motion in these moiré potentials is crucial for device applications.
Purpose of the Study:
- Investigate interlayer exciton dynamics and transport in WS2-WSe2 heterobilayers.
- Explore the influence of moiré potentials and exciton-exciton interactions on exciton motion.
Main Methods:
- Transient absorption microscopy to study exciton dynamics in time, space, and momentum domains.
- First-principles calculations to complement experimental observations.
Main Results:
- Exciton motion is modulated by twist-angle-dependent moiré potentials (~100 meV).
- Exciton transport deviates from normal diffusion due to moiré potentials and strong exciton-exciton interactions.
- Experimental results confirm energetically favorable K-Q interlayer excitons and twist-angle-dependent population dynamics.
Conclusions:
- Exciton dynamics in WS2-WSe2 heterobilayers are governed by moiré potentials and exciton interactions.
- Findings provide a basis for investigating exciton and spin transport in van der Waals heterostructures.
- Implications for designing advanced quantum communication devices.
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