Controlling spontaneous emission of a two-level atom by hyperbolic metamaterials

TL;DR

This paper investigates how hyperbolic metamaterials influence the spontaneous emission of a two-level atom, revealing tunable emission properties and significant enhancement in emission rates due to the unique dispersion relations.

Contribution

It provides an explicit analysis of decay rates considering dipole orientation in hyperbolic media, highlighting the dramatic enhancement and directivity of spontaneous emission.

Findings

Spontaneous emission can be dramatically enhanced in hyperbolic media.

Emission intensity is tunable by dipole orientation in ellipsoid cases.

Emission exhibits strong directivity with maximum in asymptote direction.

Abstract

Within the frame of quantum optics we analyze the properties of spontaneous emission of two-level atom in media with indefinite permittivity tensor where the geometry of the dispersion relation is characterized by an ellipsoid or a hyperboloid(hyperbolic medium). The decay rate is explicitly given with the orientation of the dipole transition matrix element taken into account. It indicates that for the ellipsoid case the intensity of the photons coupled into different modes can be tuned by changing the direction of the matrix element and for the hyperboloid case it is found that spontaneous emission in hyperbolic medium can be dramatically enhanced compared to the dielectric background. Moreover, spontaneous emission exhibit the strong directivity and get the maximum in the asymptote direction.