Symmetry Breaking in Haloscope Microwave Cavities

TL;DR

This paper analyzes how symmetry breaking in haloscope microwave cavities affects axion detection sensitivity, revealing that such symmetry breaking can reduce sensitivity and cause mode mixing, complicating dark matter searches.

Contribution

It provides a numerical analysis showing the negative impacts of transverse and longitudinal symmetry breaking on cavity performance.

Findings

Symmetry breaking reduces search mode sensitivity.

Longitudinal symmetry breaking causes mode mixing.

Symmetry breaking complicates axion detection efforts.

Abstract

Axion haloscope detectors use microwave cavities permeated by a magnetic field to resonate photons that are converted from axions due to the inverse Primakoff effect. The sensitivity of a detector is proportional to the form factor of the cavity's search mode. Transverse symmetry breaking is used to tune the search modes for scanning across a range of axion masses. However, numerical analysis shows transverse and longitudinal symmetry breaking reduce the sensitivity of the search mode. Simulations also show longitudinal symmetry breaking leads to other undesired consequences like mode mixing and mode crowding. The results complicate axion dark matter searches and further reduce the search capabilities of detectors. The findings of a numerical analysis of symmetry breaking in haloscope microwave cavities are presented.