Tailoring Phonon Polaritons in hBN with the Plasmonic Phase-Change Material In₃SbTe₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanophotonics

Background:

• Van-der-Waals materials (vdWMs) offer unique polariton properties but require complex lithography for structure fabrication.
• Phase-change materials (PCMs) allow for optical control and reconfigurability of material properties.
• Indium antimonide telluride (In3SbTe2) is a plasmonic PCM switchable between dielectric and metallic states.

Purpose of the Study:

• To optically program phase-change material structures for tailoring polaritons in vdWMs.
• To demonstrate the reconfigurability and performance of these optically programmed structures.
• To promote In3SbTe2 as a platform for rapid prototyping of polariton optics.

Main Methods:

• Combining hexagonal boron nitride (hBN) with In3SbTe2.
• Optically programming circular resonators in In3SbTe2 for hBN phonon polaritons.
• Investigating polariton resonators using near-field optical microscopy.

Main Results:

• Demonstrated reconfigurable polariton resonators with tunable confinement (up to λ/39).
• Achieved a high quality factor of 72 for the polariton resonators.
• Fabricated and reconfigured a focusing structure for hBN polaritons.

Conclusions:

• In3SbTe2 is a versatile material for optically programming metallic launching structures.
• This approach enables fast and reconfigurable fabrication of polariton devices.
• Facilitates rapid prototyping of polariton optics in van-der-Waals heterostructures.