Signal crosstalk in a flip-chip quantum processor
Abstract
Quantum processors require a signal-delivery architecture with high addressability (low crosstalk) to ensure high performance already at the scale of dozens of qubits. Signal crosstalk causes inadvertent driving of quantum gates, which will adversely affect quantum-gate fidelities in scaled-up devices. Here, we demonstrate packaged flip-chip superconducting quantum processors with signal-crosstalk performance competitive with those reported in other platforms. For capacitively coupled qubit-drive lines, we find on-resonant crosstalk better than -27 dB (average -37 dB). For inductively coupled magnetic-flux-drive lines, we find less than 0.13 % direct-current flux crosstalk (average 0.05 %). These observed crosstalk levels are adequately small and indicate a decreasing trend with increasing distance, which is promising for further scaling up to larger numbers of qubits. We discuss the implication of our results for the design of a low-crosstalk, on-chip signal delivery architecture, including the influence of a shielding tunnel structure, potential sources of crosstalk, and estimation of crosstalk-induced qubit-gate error in scaled-up quantum processors.
Cite
@article{arxiv.2403.00285,
title = {Signal crosstalk in a flip-chip quantum processor},
author = {Sandoko Kosen and Hang-Xi Li and Marcus Rommel and Robert Rehammar and Marco Caputo and Leif Grönberg and Jorge Fernández-Pendás and Anton Frisk Kockum and Janka Biznárová and Liangyu Chen and Christian Križan and Andreas Nylander and Amr Osman and Anita Fadavi Roudsari and Daryoush Shiri and Giovanna Tancredi and Joonas Govenius and Jonas Bylander},
journal= {arXiv preprint arXiv:2403.00285},
year = {2024}
}
Comments
21 pages, 16 figures, includes appendices, updated discussion on source of xy crosstalk, flux stability, etc