Calibration of Drive Non-Linearity for Arbitrary-Angle Single-Qubit Gates Using Error Amplification

Abstract

The ability to execute high-fidelity operations is crucial to scaling up quantum devices to large numbers of qubits. However, signal distortions originating from non-linear components in the control lines can limit the performance of single-qubit gates. In this work, we use a measurement based on error amplification to characterize and correct the small single-qubit rotation errors originating from the non-linear scaling of the qubit drive rate with the amplitude of the programmed pulse. With our hardware, and for a 15-ns pulse, the rotation angles deviate by up to several degrees from a linear model. Using purity benchmarking, we find that control errors reach $2\times 10^{-4}$, which accounts for half of the total gate error. Using cross-entropy benchmarking, we demonstrate arbitrary-angle single-qubit gates with coherence-limited errors of $2\times 10^{-4}$ and leakage below $6\times 10^{-5}$. While the exact magnitude of these errors is specific to our setup, the presented method is applicable to any source of non-linearity. Our work shows that the non-linearity of qubit drive line components imposes a limit on the fidelity of single-qubit gates, independent of improvements in coherence times, circuit design, or leakage mitigation when not corrected for.

References in corpus (20)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Charge insensitive qubit design derived from the Cooper pair box
• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Simple pulses for elimination of leakage in weakly nonlinear qubits
• Robust randomized benchmarking of quantum processes
• Realizing Repeated Quantum Error Correction in a Distance-Three Surface Code
• Exponential suppression of bit or phase flip errors with repetitive error correction
• Analytic control methods for high fidelity unitary operations in a weakly nonlinear oscillator
• Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler
• Digital quantum simulation of spin models with circuit quantum electrodynamics
• Demonstration of a High-Fidelity CNOT for Fixed-Frequency Transmons with Engineered ZZ Suppression
• Logical-qubit operations in an error-detecting surface code
• Realizing Quantum Convolutional Neural Networks on a Superconducting Quantum Processor to Recognize Quantum Phases
• High-fidelity controlled-Z gate with maximal intermediate leakage operating at the speed limit in a superconducting quantum processor
• Benchmarking Coherent Errors in Controlled-Phase Gates due to Spectator Qubits
• Fast logic with slow qubits: microwave-activated controlled-Z gate on low-frequency fluxoniums
• Unimon qubit
• IQ Mixer Calibration for Superconducting Circuits
• Radio frequency mixing modules for superconducting qubit room temperature control systems
• Nonlinear Signal Distortion Corrections Through Quantum Sensing

Cited by in corpus (11)

• Reducing leakage of single-qubit gates for superconducting quantum processors using analytical control pulse envelopes
• Fast Flux-Activated Leakage Reduction for Superconducting Quantum Circuits
• Deterministic generation of a 20-qubit two-dimensional photonic cluster state
• Active Leakage Cancellation in Single Qubit Gates
• Realizing Lattice Surgery on Two Distance-Three Repetition Codes with Superconducting Qubits
• Realizing a Continuous Set of Two-Qubit Gates Parameterized by an Idle Time
• Compact optical waveform generator with digital feedback
• In situ mixer calibration for superconducting quantum circuits
• Sub-Harmonic Control of a Fluxonium Qubit via a Purcell-Protected Flux Line
• Optimal Control of Spin Qudits Subject to Decoherence Using Amplitude-and-Frequency-Constrained Pulses
• In-situ characterization of qubit drive-phase distortions