High-performance superconducting quantum processors via laser annealing of transmon qubits
Eric Zhang, Srikanth Srinivasan, Neereja Sundaresan, Daniela F. Bogorin, Yves Martin, Jared Hertzberg, John Timmerwilke, Emily Pritchett, Jeng-Bang Yau, Cindy Wang, W. Landers, Eric P. Lewandowski, Adinath Narasgond, Sami Rosenblatt, George Keefe, Isaac Lauer, Mary Beth Rothwell, Douglas McClure, Oliver Dial, Jason S. Orcutt, Markus Brink, Jerry M. Chow
Abstract
Scaling the number of qubits while maintaining high-fidelity quantum gates remains a key challenge for quantum computing. Presently, superconducting quantum processors with >50 qubits are actively available. For these systems, fixed-frequency transmons are attractive because of their long coherence and noise immunity. However, scaling fixed-frequency architectures proves challenging because of precise relative frequency requirements. Here, we use laser annealing to selectively tune transmon qubits into desired frequency patterns. Statistics over hundreds of annealed qubits demonstrate an empirical tuning precision of 18.5 MHz, with no measurable impact on qubit coherence. We quantify gate error statistics on a tuned 65-qubit processor, with median two-qubit gate fidelity of 98.7%. Baseline tuning statistics yield a frequency-equivalent resistance precision of 4.7 MHz, sufficient for high-yield scaling beyond 10 3 qubit levels. Moving forward, we anticipate selective laser annealing to play a central role in scaling fixed-frequency architectures.