Quantum plasmonics: second-order coherence of surface plasmons launched by quantum emitters into a metallic film

TL;DR

This study investigates the quantum coherence properties of surface plasmons generated by a quantum light source on a gold film, demonstrating preservation of quantum statistics during plasmon propagation.

Contribution

It provides experimental evidence that quantum statistics of light are maintained when converted into and propagated as surface plasmons on a metallic film.

Findings

Quantum statistics are preserved after plasmon conversion.

Surface plasmons maintain second-order coherence.

Quantum emitters effectively launch coherent surface plasmons.

Abstract

We address the issue of the second-order coherence of single surface plasmons launched by a quantum source of light into extended gold films. The quantum source of light is made of a scanning fluorescent nanodiamond hosting five nitrogen-vacancy (NV) color centers. By using a specially designed microscopy that combines near-field optics with far-field leakage-radiation microscopy in the Fourier space and adapted spatial filtering, we find that the quantum statistics of the initial source of light is preserved after conversion to surface plasmons and propagation along the polycrystalline gold film.