Precision and resource scaling of real-time flux distortion compensation for superconducting quantum control

2026-09-23

AI Summary

本文提出了一种频率域逆变和时域拟合方法，以实现资源高效的实时通量失真补偿，提高超导量子电路的门保真度。

Abstract

Real-time waveform generation supports dynamic quantum circuits without pre-storing complete waveforms for every execution path. However, long-lived distortions in flux-control lines degrade gate fidelity, requiring compensation to account for the actual pulse history. A frequency-domain inversion and time-domain fitting method is proposed for resource-efficient real-time flux distortion compensation. The method fits the reconstructed compensation impulse response with a compact hybrid infinite impulse response (IIR) and finite impulse response (FIR) filter. Look-ahead parallelization enables this filter to process synthesized waveforms at 1.2GSa/s on a field-programmable gate array (FPGA). Two-qubit cross-entropy benchmarking shows that real-time IIR filtering achieves a median controlled-Z Pauli fidelity close to the software-reference value of 99.57%. Numerical analysis and FPGA synthesis indicate approximately logarithmic growth in hardware resource use with compensation timescale. Extending compensation from microsecond to hundred-microsecond timescales increases look-up table (LUT) and digital signal processing (DSP) resource use by only about 14% and 4%, respectively, while maintaining a relative arithmetic error below $10^{-4}$. This work provides a scalable hardware foundation for high-fidelity flux control in dynamic superconducting quantum circuits.

Problem

• real-time waveform generation
• flux distortion
• gate fidelity
• quantum control
• superconducting quantum circuits

Innovation

• real-time flux distortion compensation
• hybrid IIR and FIR filter
• resource-efficient
• look-ahead parallelization
• scalable hardware foundation