Flux-tunable superconducting qubits rely on fast flux control pulses to implement two-qubit entangling quantum gates, a key building block for quantum algorithms. However, distortion effects introduced by non-ideal control electronics, parasitic components, and the cryogenic quantum chip response can all degrade the gate fidelity. We present a digital predistortion (DPD) framework for characterizing and then compensating for these distortions using a combination of infinite impulse response (IIR) and finite impulse response (FIR) filters. Experiments on a flux-tunable quantum processing unit (QPU) demonstrate a successful correction of step-response distortions on the flux-control line, with a compensated control signal showing only sub-percent deviations from the ideal target linear behavior. The demonstrated method enables automated rapid calibration of flux control channels for superconducting QPUs.
@article{arxiv.2604.15895,
title = {Digital Predistortion for Flux Control of Tunable Superconducting Qubits},
author = {Dharun Venkateswaran and Felice Francesco Tafuri and Yuanzheng Paul Tan and Bruno Aznar Martinez and Alisa Danilenko and Likai Yang and Arnaud Carignan-Dugas and Christoph Hufnagel and Rainer Dumke and Philip Krantz and Eric T. Holland},
journal= {arXiv preprint arXiv:2604.15895},
year = {2026}
}
Comments
4 pages, 6 figures, submitted for EuMW 2026 Conference