Spontaneous Emission in Nonlocal Materials

TL;DR

This paper reports the first experimental observation of molecular spontaneous emission inside a highly nonlocal metamaterial, revealing that nonlocal responses significantly influence emission rates and can be engineered for advanced quantum applications.

Contribution

It demonstrates the impact of nonlocality on spontaneous emission in metamaterials, providing experimental evidence and a quantitative model for Purcell enhancement in nonlocal media.

Findings

Record-high decay rate enhancement observed.

Different geometric parameters affect Purcell factors despite identical local properties.

Nonlocal response introduces new control degrees in quantum electrodynamics.

Abstract

Light-matter interactions can be dramatically modified by the surrounding environment. Here we report on the first experimental observation of molecular spontaneous emission inside a highly nonlocal metamaterial based on a plasmonic nanorod assembly. We show that the emission process is dominated not only by the topology of its local effective medium dispersion, but also by the nonlocal response of the composite, so that metamaterials with different geometric parameters but the same local effective medium properties exhibit different Purcell factors. A record-high enhancement of a decay rate is observed, in agreement with the developed quantitative description of the Purcell effect in a nonlocal medium. An engineered material nonlocality introduces an additional degree of freedom into quantum electrodynamics, enabling new applications in quantum information processing, photo-chemistry, imaging, and sensing.