Dielectric Haloscopes to Search for Axion Dark Matter: Theoretical Foundations

TL;DR

This paper develops the theoretical basis for dielectric haloscopes, a novel method to detect axion dark matter by using layered dielectric interfaces in magnetic fields to generate detectable electromagnetic signals, especially in high-frequency ranges.

Contribution

It provides the first detailed theoretical framework for dielectric haloscopes, showing how layered dielectrics can enhance axion-induced electromagnetic emission for dark matter searches.

Findings

Derived the axion-modified Maxwell equations for dielectric interfaces.

Calculated the emission efficiency and interference effects in layered structures.

Identified potential to explore high-frequency axion mass range 40-400 μeV.

Abstract

We study the underlying theory of dielectric haloscopes, a new way to detect dark matter axions. When an interface between different dielectric media is inside a magnetic field, the oscillating axion field acts as a source of electromagnetic waves, which emerge in both directions perpendicular to the surface. The emission rate can be boosted by multiple layers judiciously placed to achieve constructive interference and by a large transverse area. Starting from the axion-modified Maxwell equations, we calculate the efficiency of this new dielectric haloscope approach. This technique could potentially search the unexplored high-frequency range of 10--100 GHz (axion mass 40--400 $\mu$eV), where traditional cavity resonators have difficulties reaching the required volume.