Practical photonic band gap structures for high frequency axion haloscopes

TL;DR

This paper presents a novel photonic band gap structure that suppresses TE modes in high-frequency axion haloscope resonators, enabling more efficient and tunable searches for dark matter axions above 5 GHz.

Contribution

It introduces a practical design for photonic band gap structures that eliminate TE modes with minimal lattice periods, improving high-frequency axion detection capabilities.

Findings

TE mode suppression achieved with minimal lattice periods

Enables tunable, volumetrically efficient resonators

Facilitates axion searches above 5 GHz

Abstract

Current and future searches for dark matter axions, based on their resonant conversion to photons in a magnetic field, span many orders of magnitude. A major impediment to designing resonators at the high end of this range, 5 GHz and above, is the proliferation of TE modes, which overwhelm and hybridize with the TM010 mode to which the axion couples, making the search impossible. We demonstrate that a photonic band gap structure can be designed that completely suppresses the TE spectrum, even reducing the number of lattice periods to two or one, and violating perfect lattice symmetry. This allows tunable resonators to be designed in a convenient, volumetrically efficient circular geometry thus enabling future searches in the post-inflation axion mass range.