Design and simulation of a transmon qubit chip for Axion detection

TL;DR

This paper details the design, simulation, and initial characterization of a superconducting transmon qubit chip aimed at detecting Axions, leveraging quantum non-demolition techniques for enhanced dark matter searches.

Contribution

It introduces the design and simulation process for a superconducting qubit device specifically tailored for Axion detection, including characterization of resonators and matching simulation models.

Findings

Achieved a maximum internal quality factor of 9.2x10^5.

Demonstrated good agreement between simulation models.

Characterized resonators suitable for quantum sensing applications.

Abstract

Quantum Sensing is a rapidly expanding research field that finds one of its applications in Fundamental Physics, as the search for Dark Matter. Devices based on superconducting qubits have already been successfully applied in detecting few-GHz single photons via Quantum Non-Demolition measurement (QND). This technique allows us to perform repeatable measurements, bringing remarkable sensitivity improvements and dark count rate suppression in experiments based on high-precision microwave photon detection, such as for Axions and Dark Photons search. In this context, the INFN Qub-IT project goal is to realize an itinerant single-photon counter based on superconducting qubits that will exploit QND for enhancing Axion search experiments. In this study, we present Qub-IT's status towards the realization of its first superconducting qubit device, illustrating design and simulation procedures and the characterization of fabricated Coplanar Waveguide Resonators (CPWs) for readout. We match target qubit parameters and assess a few-percent level agreement between lumped and distributed element simulation models. We reach a maximum internal quality factor of 9.2x10^5 for -92 dBm on-chip readout power.