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Configurable phonon polaritons in twisted α-MoO3
Mingyuan Chen1, Xiao Lin2, Thao H Dinh3
1Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, Auburn, AL, USA.
Nature Materials
|July 15, 2020
Summary
Researchers engineered tunable light-matter waves, specifically phonon polaritons, in twisted molybdenum trioxide (α-MoO3) slabs. This moiré engineering approach offers new possibilities for designing nanophotonic devices with controllable properties.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanophotonics
Background:
- Moiré engineering is crucial for tuning properties of van der Waals materials.
- Peculiar moiré superlattices form at specific twist angles, enabling property modification.
Purpose of the Study:
- To investigate configurable nanoscale light-matter waves (phonon polaritons) in twisted stacked α-phase molybdenum trioxide (α-MoO3) slabs.
- To explore the effect of twist angles on polariton behavior.
Main Methods:
- Experimental and theoretical analysis of stacked α-MoO3 slabs twisted over a wide range of angles (0° to 90°).
- Investigation of electromagnetic interactions governing polariton behavior.
Main Results:
- Demonstrated configurable phonon polaritons by twisting α-MoO3 slabs.
- Observed diverse polariton wavefront geometries and topological transitions dependent on twist angle.
- Attributed polariton modification to electromagnetic interactions of hyperbolic polaritons, distinct from electronic band structure changes in other moiré systems.
Conclusions:
- Twisted α-MoO3 serves as a versatile platform for creating tunable nanophotonic devices.
- The findings open avenues for novel optical and electromagnetic functionalities.
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