Quantum Parity Detectors: a qubit based particle detection scheme with meV thresholds for rare-event searches

TL;DR

This paper proposes quantum parity detectors (QPDs), superconducting qubit sensors capable of detecting meV-scale energy depositions for rare-event searches like dark matter and neutrino experiments.

Contribution

It introduces QPDs that utilize quasiparticle tunneling in superconducting qubits to achieve ultra-low energy thresholds and provides analysis and strategies for their implementation.

Findings

QPDs can detect energy depositions at the meV scale.

Multiple resonator readout schemes are proposed for QPDs.

An R&D pathway for sub-eV energy thresholds is outlined.

Abstract

The next generation of rare-event searches, such as those aimed at determining the nature of particle dark matter or in measuring fundamental neutrino properties, will benefit from particle detectors with thresholds at the meV scale, 100-1000x lower than currently available. Quantum parity detectors (QPDs) are a class of proposed quantum devices, extending recent work on superconducting qubit sensors, that exploit the fingerprints of single quasiparticle tunneling across a coherent weak-link as their detection concept. As envisioned, phonons generated by particle interactions within a crystalline substrate cause an eventual quasiparticle cascade within a surface-patterned superconducting qubit element. This process alters the fundamental charge parity of the device in a binary manner, which can be used to deduce the initial properties of the energy deposition. This work lays out multiple resonator coupled readout schemes depending on qubit architecture, provides an analytic formulation for reconstructing sensor energies, and details strategies for multiplexing large arrays of sensors. We further compute the sensitivity of QPDs and detail an R&D pathway to demonstrating sub-eV energy deposit thresholds.