In situ nanoscale imaging of moiré superlattices in twisted van der Waals heterostructures
Abstract
Direct visualization of nanometer-scale properties of moiré superlattices in van der Waals heterostructure devices is a critically needed diagnostic tool for study of the electronic and optical phenomena induced by the periodic variation of atomic structure in these complex systems. Conventional imaging methods are destructive and insensitive to the buried device geometries, preventing practical inspection. Here we report a versatile scanning probe microscopy employing infrared light for imaging moiré superlattices of twisted bilayers graphene encapsulated by hexagonal boron nitride. We map the pattern using the scattering dynamics of phonon polaritons launched in hexagonal boron nitride capping layers via its interaction with the buried moiré superlattices. We explore the origin of the double-line features imaged and show the mechanism of the underlying effective phase change of the phonon polariton reflectance at domain walls. The nano-imaging tool developed provides a non-destructive analytical approach to elucidate the complex physics of moiré engineered heterostructures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 21, 2020
- Source ID
- 10.1038/s41467-020-18109-0
Entities
People
- Efthimios Kaxiras
- Kenji Watanabe
- Marios Mattheakis
- Michele Tamagnone
- Philip Kim
- Rebecca Engelke
- Stephen Carr
- Takashi Taniguchi
- William L. Wilson
- Yue Luo
Organizations
- ARPA-E
- United States Department of Defense