# Piezoelectrically Tuned Multimode Cavity Search for Axion Dark Matter

## TL;DR

This paper reports on the ADMX Sidecar experiment, a pathfinder for axion dark matter detection that successfully demonstrates cavity tuning with piezoelectric actuators and measures multiple modes across several frequency ranges.

## Contribution

It introduces the use of a piezoelectric actuator for cavity tuning and reports the first measurements using both TM$_{010}$ and TM$_{020}$ modes in axion searches.

## Key findings

- Excluded axion masses in three frequency ranges.
- Demonstrated cavity tuning with piezoelectric actuators.
- First measurements with multiple cavity modes.

## Abstract

The $\mu$eV axion is a well-motivated extension to the standard model. The Axion Dark Matter eXperiment (ADMX) collaboration seeks to discover this particle by looking for the resonant conversion of dark-matter axions to microwave photons in a strong magnetic field. In this Letter, we report results from a pathfinder experiment, the ADMX "Sidecar," which is designed to pave the way for future, higher mass, searches. This testbed experiment lives inside of and operates in tandem with the main ADMX experiment. The Sidecar experiment excludes masses in three widely spaced frequency ranges (4202-4249, 5086-5799, and 7173-7203 MHz). In addition, Sidecar demonstrates the successful use of a piezoelectric actuator for cavity tuning. Finally, this publication is the first to report data measured using both the TM$_{010}$ and TM$_{020}$ modes.