Coherent coupling between surface plasmons and excitons in semiconductor nanocrystals

TL;DR

This paper demonstrates strong coupling between surface plasmons and excitons in CdSe nanocrystals on a silver substrate, revealing mixed states with potential for plasmonic non-linear devices and quantum electrodynamics studies.

Contribution

It provides the first experimental evidence of strong plasmon-exciton coupling in semiconductor nanocrystals at room temperature.

Findings

Rabi splitting of ~82 meV observed

Formation of plasmon-exciton mixed states confirmed

Potential for studying strong light-matter interactions

Abstract

We present an experimental demonstration of strong coupling between a surface plasmon propagating on a planar silver substrate, and the lowest excited state of CdSe nanocrystals. Variable-angle spectroscopic ellipsometry measurements demonstrated the formation of plasmon-exciton mixed states, characterized by a Rabi splitting of $\sim$ 82 meV at room temperature. Such a coherent interaction has the potential for the development of plasmonic non-linear devices, and furthermore, this system is akin to those studied in cavity quantum electrodynamics, thus offering the possibility to study the regime of strong light-matter coupling in semiconductor nanocrystals at easily accessible experimental conditions.