The searchlight effect in hyperbolic materials

TL;DR

This paper investigates the unique electromagnetic phenomena in hyperbolic materials, including field divergence near holes and a searchlight effect where dipoles influence each other over large distances, revealing potential for advanced control of electromagnetic interactions.

Contribution

It introduces the searchlight effect in hyperbolic media, showing how dipoles can significantly influence each other over large distances depending on their placement and frequency.

Findings

Field divergence along tangent lines near holes as loss approaches zero

Distant dipoles can strongly influence each other's moments due to the searchlight effect

Enhancement of dipole interaction can increase with distance for specific polarizabilities

Abstract

The quasistatic field around a circular hole in a two-dimensional hyperbolic medium is studied. As the loss parameter goes to zero, it is found that the electric field diverges along four lines each tangent to the hole. In this limit, the power dissipated by the field in the vicinity of these lines, per unit length of the line, goes to zero but extends further and further out so that the net power dissipated remains finite. Additionally the interaction between polarizable dipoles in a hyperbolic medium is studied. It is shown that a dipole with small polarizability can dramatically influence the dipole moment of a distant polarizable dipole, if it is appropriately placed. We call this the searchlight effect, as the enhancement depends on the orientation of the line joining the polarizable dipoles and can be varied by changing the frequency. For some particular polarizabilities the enhancement can actually increase the further the polarizable dipoles are apart.