Quantum Colloquium — Efficient Error Correction in Neutral Atoms via Erasure Conversion

Executing quantum algorithms on error-corrected logical qubits is a critical step for scalable quantum computing, but the requisite numbers of qubits and physical error rates are demanding for current experimental hardware. Recently, the development of error correcting codes tailored to particular physical noise models has helped relax these requirements, exemplified by the case of biased noise in bosonic superconducting qubits. In this talk, I will discuss our recent proposal for a novel neutral atom qubit using Yb-171, which allows the dominant physical errors to be converted into erasures, that is, errors in known locations [1]. The key idea is to encode qubits in a metastable electronic level, such that gate errors predominantly result in transitions to disjoint subspaces whose populations can be continuously monitored via fluorescence. Using realistic experimental parameters, we estimate that 98% of errors can be converted into erasures. We quantify the benefit of this approach via circuit-level simulations of the surface code, finding a threshold increase from 0.937% to 4.15%. Importantly, achieving a circuit-level benefit does not require bias-preserving gates. I will also discuss ongoing work towards an experimental implementation of these qubits [2], as well as prospects for converting a wider range of errors into erasures. [1] Y. Wu, S. Kolkowitz, S. Puri, and J. D. Thompson, arxiv:2201.03540 (2022). [2] S. Ma, A. P. Burgers, G. Liu, J. Wilson, B. Zhang, and J. D. Thompson, arxiv:2112.06799 (2021).

Panel discussion: Kenneth Brown (Duke University), Ignacio Cirac (Max Planck Institute of Quantum Optics), Liang Jiang (University of Chicago), Mark Saffman (UW Madison), Umesh Vazirani (UC Berkeley; moderator)