Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier

Abstract

High-fidelity and rapid readout of a qubit state is key to quantum computing and communication, and it is a prerequisite for quantum error correction. We present a readout scheme for superconducting qubits that combines two microwave techniques: applying a shelving technique to the qubit that effectively increases the energy-relaxation time, and a two-tone excitation of the readout resonator to distinguish among qubit populations in higher energy levels. Using a machine-learning algorithm to post-process the two-tone measurement results further improves the qubit-state assignment fidelity. We perform single-shot frequency-multiplexed qubit readout, with a 140ns readout time, and demonstrate 99.5% assignment fidelity for two-state readout and 96.9% for three-state readout - without using a quantum-limited amplifier.

References in corpus (17)

• Charge insensitive qubit design derived from the Cooper pair box
• Surface codes: Towards practical large-scale quantum computation
• Resolving photon number states in a superconducting circuit
• Simple pulses for elimination of leakage in weakly nonlinear qubits
• AC-Stark Shift and Dephasing of a Superconducting Qubit Strongly Coupled to a Cavity Field
• Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting
• Single-shot qubit readout in circuit Quantum Electrodynamics
• Single-shot qubit readout in circuit Quantum Electrodynamics
• High-Fidelity Readout in Circuit Quantum Electrodynamics Using the Jaynes-Cummings Nonlinearity
• Analytic control methods for high fidelity unitary operations in a weakly nonlinear oscillator
• Coherence and Decay of Higher Energy Levels of a Superconducting Transmon Qubit
• Initialization by measurement of a two-qubit superconducting circuit
• Fast readout and reset of a superconducting qubit coupled to a resonator with an intrinsic Purcell filter
• Machine learning for discriminating quantum measurement trajectories and improving readout
• Measurement-induced qubit state mixing in circuit QED from up-converted dephasing noise
• Enhancing qubit readout through dissipative sub-Poissonian dynamics
• General error mitigation for quantum circuits

Cited by in corpus (46)

• Measurement-Induced Transmon Ionization
• Enhancing Dispersive Readout of Superconducting Qubits Through Dynamic Control of the Dispersive Shift: Experiment and Theory
• Fast single atom imaging for optical lattice arrays
• Model-based Optimization of Superconducting Qubit Readout
• Optical readout of a superconducting qubit using a piezo-optomechanical transducer
• Systematic study of High $E_J/E_C$ transmon qudits up to $d=12$
• Benchmarking the readout of a superconducting qubit for repeated measurements
• Broadband Bandpass Purcell Filter for Circuit Quantum Electrodynamics
• Multi-frequency control and measurement of a spin-7/2 system encoded in a transmon qudit
• Benchmarking quantum logic operations relative to thresholds for fault tolerance
• Optimal control in large open quantum systems: the case of transmon readout and reset
• Improving Transmon Qudit Measurement on IBM Quantum Hardware
• Qubit readouts enabled by qubit cloaking
• Quantum SWAP gate realized with CZ and iSWAP gates in a superconducting architecture
• Stochastic waveform estimation at the fundamental quantum limit
• Enhancing Qubit Readout with Autoencoders
• Simulation of Quantum Computers: Review and Acceleration Opportunities
• Mitigating Errors on Superconducting Quantum Processors through Fuzzy Clustering
• Estimating the Energy Threshold of Phonon-mediated Superconducting Qubit Detectors Operated in an Energy-Relaxation Sensing Scheme
• Characterization of Broadband Purcell Filters with Compact Footprint for Fast Multiplexed Superconducting Qubit Readout
• Many-excitation removal of a transmon qubit using a single-junction quantum-circuit refrigerator and a two-tone microwave drive
• Digital homodyne and heterodyne detection for stationary bosonic modes
• Parametric multi-element coupling architecture for coherent and dissipative control of superconducting qubits
• Transmon-qubit readout using in-situ bifurcation amplification in the mesoscopic regime
• Directional emission of a readout resonator for qubit measurement
• Recovering Quantum Coherence of a Cavity Qubit Coupled to a Noisy Ancilla through Real-Time Feedback
• Enhancing qubit readout with Bayesian Learning
• On the Impact of Classical and Quantum Communication Networks Upon Modular Quantum Computing Architecture System Performance
• Practical Trainable Temporal Postprocessor for Multistate Quantum Measurement
• Heralding entangled optical photons from a microwave quantum processor
• Cross-platform hardware benchmark of style-based quantum GANs for data augmentation on superconducting and trapped-ion processors
• Leakage in restless quantum gate calibration
• On-demand shaped photon emission based on a parametrically modulated qubit
• Above 99.9% Fidelity Single-Qubit Gates, Two-Qubit Gates, and Readout in a Single Superconducting Quantum Device
• Flexible Readout and Unconditional Reset for Superconducting Multi-Qubit Processors with Tunable Purcell Filters
• Parity-protected superconducting qubit based on topological insulators
• Multimode Purcell Filter for Superconducting-Qubit Reset and Readout with Intrinsic Purcell Protection
• Tutorial on Superconducting Quantum Circuits: From Basics to Applications
• Simulation of a rapid qubit readout dependent on the transmission of a single fluxon
• Protecting entanglement witnesses with randomized measurements
• Model Order Reduction for Open Quantum Systems Based on Measurement-adapted Time-coarse Graining
• Mitigating Measurement Crosstalk via Pulse Shaping
• Geometric Phase of a Transmon in a Dissipative Quantum Circuit
• Bosonic Entanglement and Quantum Sensing from Energy Transfer in two-tone Floquet Systems
• Low-rank optimal control of quantum devices
• Mitigating errors in state preparation and measurement with noncomputational states