Exploring the Fidelity of Flux Qubit Measurement in Different Bases via the Quantum Flux Parametron

Abstract

High-fidelity qubit readout is a fundamental requirement for practical quantum computing systems. In this work, we investigate methods to enhance the measurement fidelity of flux qubits via a quantum flux parametron-mediated readout scheme. Through theoretical modeling and numerical simulations, we analyze the impact of different measurement bases on fidelity in single-qubit and coupled two-qubit systems. For single-qubit systems, we show that energy bases consistently outperform flux bases in achieving higher fidelity. In coupled two-qubit systems, we explore two measurement models: sequential and simultaneous measurements, both aimed at reading out a single target qubit. Our results indicate that the highest fidelity can be achieved either by performing sequential measurement in a dressed basis over a longer duration or by conducting simultaneous measurement in a bare basis over a shorter duration. Importantly, the sequential measurement model consistently yields more robust and higher fidelity readouts compared to the simultaneous approach. These findings quantify achievable fidelities and provide valuable guidance for optimizing measurement protocols in emerging quantum computing architectures.

References in corpus (27)

• Charge insensitive qubit design derived from the Cooper pair box
• Circuit Quantum Electrodynamics
• Noisy intermediate-scale quantum (NISQ) algorithms
• Microwave photonics with superconducting quantum circuits
• Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting
• Dispersive regime of circuit QED: photon-dependent qubit dephasing and relaxation rates
• Quantum trajectory approach to circuit QED: Quantum jumps and the Zeno effect
• Observation of classical-quantum crossover of 1/f flux noise and its paramagnetic temperature dependence
• Measurement-induced qubit state mixing in circuit QED from up-converted dephasing noise
• Josephson parametric phase-locked oscillator and its application to dispersive readout of superconducting qubits
• Enhancing Dispersive Readout of Superconducting Qubits Through Dynamic Control of the Dispersive Shift: Experiment and Theory
• Evolution of $1/f$ Flux Noise in Superconducting Qubits with Weak Magnetic Fields
• Long-range coupling and scalable architecture for superconducting flux qubits
• Model-based Optimization of Superconducting Qubit Readout
• Photon-noise-tolerant dispersive readout of a superconducting qubit using a nonlinear Purcell filter
• Analytic Design of Accelerated Adiabatic Gates in Realistic Qubits: General Theory and Applications to Superconducting Circuits
• Microwave-multiplexed qubit controller using adiabatic superconductor logic
• Fast, Lifetime-Preserving Readout for High-Coherence Quantum Annealers
• Optimizing Quantum Algorithms on Bipotent Architectures
• Anneal-path correction in flux qubits
• Algorithm-Oriented Qubit Mapping for Variational Quantum Algorithms
• Enhanced Qubit Readout via Reinforcement Learning
• Synergistic Dynamical Decoupling and Circuit Design for Enhanced Algorithm Performance on Near-Term Quantum Devices
• Improving the Performance of Digitized Counterdiabatic Quantum Optimization via Algorithm-Oriented Qubit Mapping
• What is measured when a qubit measurement is performed on a multi-qubit chip?
• Decoherence of a tunable capacitively shunted flux qubit
• Beyond the Projection Postulate and Back: Quantum Theories with Generalised State-Update Rules