Observation of acoustic magneto-chiral anisotropy in $\alpha$-quartz

TL;DR

This paper reports the first experimental observation of magneto-chiral anisotropy in ultrasound propagation in $ ext{alpha}$-quartz, using a highly sensitive spectrometer and a macroscopic analytical model.

Contribution

First experimental detection of acoustic magneto-chiral anisotropy in $ ext{alpha}$-quartz with a novel high-resolution spectrometer and a simple analytical model.

Findings

Observed magneto-chiral anisotropy in ultrasound in $ ext{alpha}$-quartz

Developed a spectrometer with resolution of $ ext{10}^{-8}$

Presented a macroscopic Becquerel-like model explaining the effect

Abstract

We report the experimental observation of magneto-chiral anisotropy in the longitudinal and transverse ultrasound propagation in $\alpha$-quartz. To perform such measurement, we have built an ultrasound spectrometer with unprecedented experimental resolution of the order of $\Delta v/v \sim 10^{-8}$. We present a simple macroscopic Becquerel-like analytical model that accounts for the magnitude of the observed effect and its frequency dependence.