Listening For New Physics With Quantum Acoustics

TL;DR

This paper proposes a quantum acoustics-based detector using superconducting qubits and acoustic resonators to search for ultralight dark matter and high-frequency gravitational waves, offering a new approach in the GHz range.

Contribution

It introduces a novel quantum acoustics detector design that can detect new physics signals like dark matter and gravitational waves in the GHz frequency range.

Findings

Prototype detector design and operation detailed

Next-generation detector can improve sensitivity for dark matter searches

Potential to operate as a threshold phonon sensor for sub-GeV dark matter

Abstract

We present a novel application of a qubit-coupled phonon detector to search for new physics, e.g., ultralight dark matter (DM) and high-frequency gravitational waves. The detector, motivated by recent advances in quantum acoustics, is composed of superconducting transmon qubits coupled to high-overtone bulk acoustic resonators ($h$BARs) and operates in the GHz - 10 GHz frequency range. New physics can excite $O(10 \, \mu \text{eV})$ phonons within the $h$BAR, which are then converted to qubit excitations via a transducer. We detail the design, operation, backgrounds, and expected sensitivity of a prototype detector, as well as a next-generation detector optimized for new physics signals. We find that a future detector can complement current haloscope experiments in the search for both dark photon DM and high-frequency gravitational waves. Lastly we comment on such a detector's ability to operate as a $10 \, \mu\text{eV}$ threshold athermal phonon sensor for sub-GeV DM detection.