Superradiance, subradiance, and suppressed superradiance of dipoles near a metal interface

TL;DR

This paper theoretically investigates how classical dipoles near a dielectric interface exhibit superradiance, subradiance, and suppressed superradiance, with potential for controlling emission via external fields, relevant for plasmonic applications.

Contribution

It introduces a theoretical framework for collective radiative behaviors of dipoles near interfaces, demonstrating enhanced and suppressed emission modes and control mechanisms.

Findings

Superradiance intensity scales as N^2 with a factor A=240 in practical cases.

Certain collective modes exhibit two orders of magnitude suppression in emission.

A method to switch between superradiant and subradiant states using external fields is proposed.

Abstract

We theoretically characterize the collective radiative behaviour of N classical emitters near an interface between different dielectrics that supports the transfer of surface plasmon modes into the far-field of electromagnetic radiation. The phenomena of superradiance and surface plasmons can be combined to amplify the emitted radiation intensity S as S= A N^2 S_0 compared to a single emitter's intensity S_0 in free space. For a practical case study within the paper A=240, compared to A=1 in free space. We furthermore demonstrate that there are collective modes for which the intensity of the emitted radiation is suppressed by two orders of magnitude despite their supperadiant emission characteristics. A method to control the emission characteristics of the system and to switch from super- to sub-radiant behaviour with a suitably detuned external driving field is devised.