Magnetic hyperbolic metamaterial of polaritonic nanowires

TL;DR

This paper demonstrates a magnetic hyperbolic metamaterial made of polaritonic nanowires, showing a topological transition in dispersion that leads to high electromagnetic density and enhanced magnetic dipole emission.

Contribution

It introduces a novel magnetic hyperbolic metamaterial using polaritonic nanowires and analyzes its topological transition affecting electromagnetic properties.

Findings

Resonant axial magnetic permeability in nanowire medium.

Sign change of permeability at a specific frequency.

High electromagnetic density and Purcell factor near transition.

Abstract

We show that the axial component of the magnetic permeability tensor is resonant for a wire medium consisting of high-index epsilon-positive nanowires, and its real part changes the sign at a certain frequency. At this frequency the medium experiences the topological transition from the hyperbolic to the elliptic type of dispersion. We show that the transition regime is characterized by extremely strong dependence of the permeability on the wave vector. This implies very high density of electromagnetic states that results in the filamentary pattern and noticeable Purcell factor for a transversely oriented magnetic dipole.