High-fidelity superconducting quantum processors via laser-annealing of transmon qubits

Eric J. Zhang; Srikanth Srinivasan; Neereja Sundaresan; Daniela F. Bogorin; Yves Martin; Jared B. Hertzberg; John Timmerwilke; Emily J. Pritchett; Jeng-Bang Yau; Cindy Wang; William Landers; Eric P. Lewandowski; Adinath Narasgond; Sami Rosenblatt; George A. Keefe; Isaac Lauer; Mary Beth Rothwell; Douglas T. McClure; Oliver E. Dial; Jason S. Orcutt; Markus Brink; Jerry M. Chow

arXiv · 2012.08475

High-fidelity superconducting quantum processors via laser-annealing of transmon qubits

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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 such systems, fixed-frequency transmons are attractive due to their long coherence and noise immunity. However, scaling fixed-frequency architectures proves challenging due to precise relative frequency requirements. Here we employ 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 1000-qubit levels. Moving forward, we anticipate selective laser annealing to play a central role in scaling fixed-frequency architectures.

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Eric J. Zhang, Srikanth Srinivasan, Neereja Sundaresan, Daniela F. Bogorin, Yves Martin, Jared B. Hertzberg, John Timmerwilke, Emily J. Pritchett, Jeng-Bang Yau, Cindy Wang, William Landers, Eric P. Lewandowski, Adinath Narasgond, Sami Rosenblatt, George A. Keefe, Isaac Lauer, Mary Beth Rothwell, Douglas T. McClure, Oliver E. Dial, Jason S. Orcutt, Markus Brink, Jerry M. Chow. 2020-12-15. High-fidelity superconducting quantum processors via laser-annealing of transmon qubits. https://arxiv.org/abs/2012.08475

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