# Plasmon-Exciton Coupling Using DNA Templates

## TL;DR

This paper demonstrates precise control of plasmon-exciton hybrid states using DNA origami to assemble metallic nanoparticles, achieving strong coupling and significant mode splitting at room temperature.

## Contribution

It introduces a novel DNA origami-based method for assembling plasmon-exciton nanostructures with tunable resonance and strong coupling capabilities.

## Key findings

- Achieved strong plasmon-exciton coupling with up to 170 meV mode splitting.
- Demonstrated tunability of plasmon resonance by varying nanoparticle size.
- Enabled room-temperature operation of plasmon-exciton systems.

## Abstract

Coherent energy exchange between plasmons and excitons is a phenomenon that arises in the strong coupling regime resulting in distinct hybrid states. The DNA-origami technique provides an ideal framework to custom-tune plasmon-exciton nanostructures. By employing this well controlled self-assembly process, we realized hybrid states by precisely positioning metallic nanoparticles in a defined spatial arrangement with fixed nanometer-sized interparticle spacing. Varying the nanoparticle diameter between 30 nm and 60 nm while keeping their separation distance constant allowed us to precisely adjust the plasmon resonance of the structure to accurately match the energy frequency of a J-aggregate exciton. With this system we obtained strong plasmon-exciton coupling and studied far-field scattering at the single-structure level. The individual structures displayed normal mode splitting up to 170 meV. The plasmon tunability and the strong field confinement attained with nanodimers on DNA-origami renders an ideal tool to bottom-up assembly plasmon-exciton systems operating at room temperature.