Mitigation of frequency collisions in superconducting quantum processors
Artikel i vetenskaplig tidskrift, 2023

The reproducibility of qubit parameters is a challenge for scaling up superconducting quantum processors. Signal cross talk imposes constraints on the frequency separation between neighboring qubits. The frequency uncertainty of transmon qubits arising from the fabrication process is attributed to deviations in the Josephson junction area, tunnel barrier thickness, and the qubit shunt capacitor. We decrease the sensitivity to these variations by fabricating larger Josephson junctions and reduce the wafer-level standard deviation in resistance down to 2%. We characterize 32 identical transmon qubits and demonstrate the reproducibility of the qubit frequencies with a 40 MHz standard deviation (i.e., 1%) with qubit quality factors exceeding 2 million. We perform two-level-system (TLS) spectroscopy and observe no significant increase in the number of TLSs causing qubit relaxation. We further show by simulation that for our parametric-gate architecture, and accounting only for errors caused by the uncertainty of the qubit frequency, we can scale up to 100 qubits with an average of only three collisions between quantum-gate transition frequencies, assuming 2% cross talk and 99.9% target gate fidelity.

Författare

Amr Osman

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Jorge Fernández-Pendás

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Christopher Warren

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Sandoko Kosen

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Marco Scigliuzzo

Ecole Polytechnique Federale de Lausanne (EPFL)

Anton Frisk Kockum

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Giovanna Tancredi

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Anita Fadavi Roudsari

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Jonas Bylander

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Physical Review Research

26431564 (ISSN)

Vol. 5 4 043001

Ämneskategorier

Annan fysik

Den kondenserade materiens fysik

DOI

10.1103/PhysRevResearch.5.043001

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Senast uppdaterat

2024-06-18