Spontaneous emission in the presence of a spherical plasmonic cloak

TL;DR

This paper studies how a spherical plasmonic cloak affects the spontaneous emission rate of a nearby atom, showing that under certain conditions, the emission can be suppressed to vacuum levels, enabling atomic probes for cloak efficiency.

Contribution

It demonstrates that atomic spontaneous emission can be controlled by plasmonic cloaks, proposing atoms as local probes for cloak performance.

Findings

Spontaneous emission can be reduced to vacuum levels near a plasmonic cloak.

The effect depends on the atomic emission frequency and cloak properties.

Atoms with strong transitions can serve as quantum probes for cloaking efficiency.

Abstract

We investigate the spontaneous emission of a two-level atom placed in the vicinities of a plasmonic cloak composed of a coated sphere. In the dipole approximation, we show that the spontaneous emission rate can be reduced to its vacuum value provided the atomic emission frequency lies within the plasmonic cloak frequency operation range. Considering the current status of plasmonic cloaking devices, this condition may be fulfilled for many atomic species so that we argue that atoms with a sufficiently strong transition can be used as quantum, local probes for the efficiency of plasmonic cloaks.