Laser-annealing Josephson junctions for yielding scaled-up superconducting quantum processors

By J. Hertzberg, E. Zhang, S. Rosenblatt, Easwar Magesan, John A. Smolin, J. Yau, V. Adiga, M. Sandberg, M. Brink, Jerry M. Chow and 1 more. npj Quantum Information, 2020

216 citations recorded by the source corpus.

As superconducting quantum circuits scale to larger sizes, the problem of frequency crowding proves a formidable task. Here we present a solution for this problem in fixed-frequency qubit architectures. By systematically adjusting qubit frequencies post-fabrication, we show a nearly tenfold improvement in the precision of setting qubit frequencies. To assess scalability, we identify the types of “frequency collisions” that will impair a transmon qubit and cross-resonance gate architecture. Using statistical modeling, we compute the probability of evading all such conditions, as a function of qubit frequency precision. We find that, without post-fabrication tuning, the probability of finding a workable lattice quickly approaches 0. However, with the demonstrated precisions it is possible to find collision-free lattices with favorable yield. These techniques and models are currently employed in available quantum systems and will be indispensable as systems continue to scale to larger sizes.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/4a567bdee5623ff42f4ffca859017d698d2c5c39

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Citations in the corpus

The future of quantum computing with superconducting qubits (2022, methodology): “We can take advantage of these statistical correlations wherever they exist for rapid progress in parts of our process 112 or in post-process tuning 113 .”
High-threshold and low-overhead fault-tolerant quantum memory (2023, background): “Qubits in cross-resonance gates are not tuneable and as such for a large device with many connections the probability of a energy collisions (not just the qubit levels but also higher levels of the transmon) trends to one very quickly 54 .”