Correlated frequency noise in a multimode acoustic resonator

TL;DR

This paper investigates frequency fluctuations in a multimode surface acoustic wave resonator, revealing correlated noise from TLS defects and anomalous bursts akin to cosmic radiation, impacting quantum device stability.

Contribution

It provides the first detailed analysis of multimode frequency noise correlations and identifies two distinct noise mechanisms affecting quantum device performance.

Findings

TLS-induced noise shows significant correlations that decrease with detuning

Strong anomalous frequency fluctuations with anti-correlated dynamics observed

Noise bursts resemble cosmic radiation signatures in superconducting systems

Abstract

Frequency instabilities are a major source of errors in quantum devices. This study investigates frequency fluctuations in a surface acoustic wave (SAW) resonator, where reflection coefficients of 14 SAW modes are measured simultaneously for more than seven hours. We report two distinct noise characteristics. Multimode frequency noise caused by interactions with two-level system (TLS) defects shows significant degrees of correlations that diminish with increased detuning. This finding agrees with the current understanding of the parasitic TLS behavior as one of the dominant noise sources in quantum devices. In addition to the TLS-induced noise, we observe strong anomalous frequency fluctuations with slow, anti-correlated dynamics. These noise bursts resemble signatures of cosmic radiation observed in superconducting quantum systems.