# Plasmon-Exciton Interactions Probed Using Spatial Coentrapment of Nanoparticles by Topological Singularities

## TL;DR

This paper demonstrates how topological singularities can be used to spatially confine and probe plasmon-exciton interactions in nanoparticles, revealing enhanced fluorescence and suppressed blinking due to the Purcell effect.

## Contribution

It introduces a novel method of using topological singularities for precise manipulation and optical probing of plasmon-exciton interactions in colloidal nanoparticles.

## Key findings

- Fluorescence of nanoparticles increases near topological singularities.
- Blinking is significantly suppressed, indicating stabilized emission.
- Radiative decay rate increases by nearly an order of magnitude.

## Abstract

We study plasmon-exciton interaction by using topological singularities to spatially confine, selectively deliver, cotrap and optically probe colloidal semiconductor and plasmonic nanoparticles. The interaction is monitored in a single quantum system in the bulk of a liquid crystal medium where nanoparticles are manipulated and nanoconfined far from dielectric interfaces using laser tweezers and topological configurations are spatially colocated with a plasmonic gold nanoburst particle in a topological singularity core, its fluorescence increases because blinking is significantly suppressed and the radiative decay rate increases by nearly an order of magnitude owing to the Purcell effect. We argue that the blinking suppression is the result of the radiative rate change that mitigates Auger recombination and quantum dot ionization, consequently reducing nonradiative recombination. Our work demonstrates that topological singularities are an effective platform for studying and controlling plasmon-exciton interactions.