General method for extracting the quantum efficiency of dispersive qubit readout in circuit QED

Abstract

We present and demonstrate a general three-step method for extracting the quantum efficiency of dispersive qubit readout in circuit QED. We use active depletion of post-measurement photons and optimal integration weight functions on two quadratures to maximize the signal-to-noise ratio of the non-steady-state homodyne measurement. We derive analytically and demonstrate experimentally that the method robustly extracts the quantum efficiency for arbitrary readout conditions in the linear regime. We use the proven method to optimally bias a Josephson traveling-wave parametric amplifier and to quantify different noise contributions in the readout amplification chain.

10 pages, 6 figures

References in corpus (13)

• Charge insensitive qubit design derived from the Cooper pair box
• Amplification and squeezing of quantum noise with a tunable Josephson metamaterial
• Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting
• Observation of quantum jumps in a superconducting artificial atom
• Realizing Rapid, High-Fidelity, Single-Shot Dispersive Readout of Superconducting Qubits
• Demonstration of Universal Parametric Entangling Gates on a Multi-Qubit Lattice
• Quantum back-action of variable-strength measurement
• Experimental demonstration of fault-tolerant state preparation with superconducting qubits
• Scalable quantum circuit and control for a superconducting surface code
• Quantum limited amplification and entanglement in coupled nonlinear resonators
• Initialization by measurement of a two-qubit superconducting circuit
• Machine learning for discriminating quantum measurement trajectories and improving readout
• Extensible 3D architecture for superconducting quantum computing

Cited by in corpus (45)

• Circuit Quantum Electrodynamics
• A Quantum Engineer's Guide to Superconducting Qubits
• Rapid high-fidelity multiplexed readout of superconducting qubits
• Computational advantage of quantum random sampling
• Gated conditional displacement readout of superconducting qubits
• Noisy intermediate-scale quantum computers
• High-fidelity controlled-Z gate with maximal intermediate leakage operating at the speed limit in a superconducting quantum processor
• Entanglement Stabilization using Parity Detection and Real-Time Feedback in Superconducting Circuits
• Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier
• Experimental demonstration of continuous quantum error correction
• Protecting quantum entanglement from leakage and qubit errors via repetitive parity measurements
• Josephson Array Mode Parametric Amplifier
• Enhancing Dispersive Readout of Superconducting Qubits Through Dynamic Control of the Dispersive Shift: Experiment and Theory
• Readout of a quantum processor with high dynamic range Josephson parametric amplifiers
• Efficient qubit measurement with a nonreciprocal microwave amplifier
• Efficient and Low-Backaction Quantum Measurement Using a Chip-Scale Detector
• Ideal Quantum Nondemolition Readout of a Flux Qubit Without Purcell Limitations
• Engineering, control and longitudinal readout of Floquet qubits
• Gate-tunable kinetic inductance parametric amplifier
• Quantum-tailored machine-learning characterization of a superconducting qubit
• Observing a Topological Transition in Weak-Measurement-Induced Geometric Phases
• Fast multiplexed superconducting qubit readout with intrinsic Purcell filtering
• Intermodulation Distortion in a Josephson Traveling Wave Parametric Amplifier
• Reducing the error rate of a superconducting logical qubit using analog readout information
• Anti-crosstalk high-fidelity state discrimination for superconducting qubits
• Sequential dispersive measurement of a superconducting qubit
• Single-Shot Readout and Weak Measurement of a Tin-Vacancy Qubit in Diamond
• Wideband Josephson Parametric Isolator
• Optimal control in large open quantum systems: the case of transmon readout and reset
• An rf-SQUID-based traveling-wave parametric amplifier with -84 dBm input saturation power across more than one octave bandwidth
• Qubit readouts enabled by qubit cloaking
• Noise reduction in qubit readout with a two-mode squeezed interferometer
• Directional emission of a readout resonator for qubit measurement
• Hamiltonian Learning using Machine Learning Models Trained with Continuous Measurements
• Robustness of longitudinal transmon readout to ionization
• Balanced cross-Kerr coupling for superconducting qubit readout
• Above 99.9% Fidelity Single-Qubit Gates, Two-Qubit Gates, and Readout in a Single Superconducting Quantum Device
• Resource-Efficient Cross-Platform Verification with Modular Superconducting Devices
• Wireless Josephson parametric amplifier above 20 GHz
• Flexible Readout and Unconditional Reset for Superconducting Multi-Qubit Processors with Tunable Purcell Filters
• Mitigating Measurement Crosstalk via Pulse Shaping
• Dispersive Qubit Readout with Intrinsic Resonator Reset
• Mitigating state transition errors during readout with a synchronized flux pulse
• Low-rank optimal control of quantum devices
• Energetic cost of measurements using quantum, coherent, and thermal light