Jump Chaotic Behaviour of Ultra Low Loss Bulk Acoustic Wave Cavities

TL;DR

This paper reports the discovery of a new nonlinear chaotic phenomenon in ultra-low loss quartz bulk acoustic wave cavities at very low temperatures, showing multiple stable states and random jumps influenced by signal frequency.

Contribution

It uncovers a previously unobserved nonlinear behavior in high-Q acoustic cavities that cannot be explained by standard models, expanding understanding of their dynamics.

Findings

Multiple stable equilibria observed in the cavity.

Random jumps between quasi states controlled by signal frequency.

Phenomenon occurs only below 20 mK and at weak pumping.

Abstract

We demonstrate a previously unobserved nonlinear phenomenon in an ultra-low loss quartz Bulk Acoustic Wave cavity ($Q>3\times10^9$), which only occurs below 20 milli-Kelvin in temperature and under relatively weak pumping. The phenomenon reveals the emergence of several stable equilibria (at least two foci and two nodes) and jumps between these quasi states at random times. The degree of this randomness as well as separations between levels can be controlled by the frequency of the incident carrier signal. It is demonstrated that the nature of the effect lays beyond the standard Duffing model.