First design of a superconducting qubit for the QUB-IT experiment

TL;DR

This paper presents the design and simulation of the first superconducting transmon qubit coupled to a resonator, aimed at advancing quantum sensing and single-photon detection for fundamental physics experiments.

Contribution

It introduces a novel superconducting qubit design for the QUB-IT project, utilizing Qiskit-Metal and EPR simulation to optimize circuit parameters for quantum sensing applications.

Findings

Successful extraction of circuit Hamiltonian parameters

Design of a superconducting qubit-resonator system

Potential for improved quantum photon detection

Abstract

Quantum sensing is a rapidly growing field of research which is already improving sensitivity in fundamental physics experiments. The ability to control quantum devices to measure physical quantities received a major boost from superconducting qubits and the improved capacity in engineering and fabricating this type of devices. The goal of the QUB-IT project is to realize an itinerant single-photon counter exploiting Quantum Non Demolition (QND) measurements and entangled qubits, in order to surpass current devices in terms of efficiency and low dark-count rates. Such a detector has direct applications in Axion dark-matter experiments (such as QUAX[1]), which require the photon to travel along a transmission line before being measured. In this contribution we present the design and simulation of the first superconducting device consisting of a transmon qubit coupled to a resonator using Qiskit-Metal (IBM). Exploiting the Energy Participation Ratio (EPR) simulation we were able to extract the circuit Hamiltonian parameters, such as resonant frequencies, anharmonicity and qubit-resonator couplings.