Generating Phase Singularities Using Surface Exciton Polaritons in an Organic Natural Hyperbolic Material

Area of Science:

• Condensed matter physics
• Materials science
• Optics

Background:

• Surface polaritons (SPs) are electromagnetic waves localized at material surfaces.
• Hyperbolic SPs exist in anisotropic materials with opposite permittivity signs.
• Organic materials offer potential for novel polaritonic applications.

Purpose of the Study:

• To experimentally investigate hyperbolic surface exciton polaritons (HSEPs) for the first time.
• To explore the intensity and phase response of HSEPs in TDBC.
• To analyze the topological properties of hyperbolic vs. nonhyperbolic SPs.

Main Methods:

• Experimental study of HSEPs in the J-aggregate TDBC (a type-II natural hyperbolic material).
• Analysis of intensity and phase response of HSEPs.
• Theoretical prediction of analogous effects in hexagonal boron nitride.

Main Results:

• First experimental observation and characterization of HSEPs.
• Demonstration that HSEPs can generate phase singularities due to the hyperbolic nature of TDBC.
• Observation of topological distinctness between hyperbolic and nonhyperbolic SPs based on their response.

Conclusions:

• Organic materials, specifically TDBC, serve as a viable platform for exploring hyperbolic surface polaritonics.
• HSEPs exhibit unique phase singularity behavior and topological properties.
• The findings pave the way for new applications in visible-frequency polaritonics.