Multiple and spectrally robust photonic magic angles in reconfigurable α-MoO₃ trilayers

Area of Science:

• Condensed matter physics
• Nanophotonics
• Materials science

Background:

• Polaritonic dispersion in twisted van der Waals materials exhibits topological transitions at a 'photonic magic angle'.
• This transition enables diffractionless polariton propagation (canalization) with deep-subwavelength resolution, promising nanoscale light control.
• Existing methods are limited by a single, fixed canalization direction per frequency, restricting practical applications.

Purpose of the Study:

• To overcome the limitation of a single photonic magic angle in controlling polariton canalization.
• To demonstrate reconfigurable and spectrally robust multiple photonic magic angles.
• To enable on-demand programming of polariton canalization direction in a single device.

Main Methods:

• Fabrication of reconfigurable twisted α-phase molybdenum trioxide (α-MoO₃) trilayers.
• Investigation of polaritonic dispersion and topological transitions in the trilayer system.
• Experimental demonstration of tunable polariton canalization at multiple frequencies and angles.

Main Results:

• Demonstration of multiple, spectrally robust photonic magic angles in twisted α-MoO₃ trilayers.
• Achieved programmable polariton canalization along any desired in-plane direction.
• Broad spectral ranges for controlled canalization were observed.

Conclusions:

• Reconfigurable twisted trilayers overcome the fixed-direction limitation of bilayers for polariton canalization.
• This work enables on-demand nanoscale light control for advanced nanophotonics applications.
• Potential applications include thermal management, nanoimaging, and quantum emitter entanglement.