Improved error correction with leakage reduction units built into qubit measurement in a superconducting quantum processor

• URL: http://arxiv.org/abs/2511.17460v1
• Date: Fri, 21 Nov 2025 18:02:36 GMT
• Title: Improved error correction with leakage reduction units built into qubit measurement in a superconducting quantum processor
• Authors: Yuejie Xin, Sean L. M. van der Meer, Marc Serra-Peralta, Tim H. F. Vroomans, Matvey Finkel, Hendrik M. Veen, Mark W. Beekman, Leonardo DiCarlo,
• Abstract summary: Leakage to non-computational states is a source of correlated errors in both time and space.<n>We present and experimentally demonstrate a high-fidelity, leakage reduction unit (LRU) operating concurrently with transmon measurement.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Leakage to non-computational states is a source of correlated errors in both time and space that limits the effectiveness of quantum error correction (QEC) with superconducting circuits. We present and experimentally demonstrate a high-fidelity, leakage reduction unit (LRU) operating concurrently with transmon measurement without incurring time overhead. Adapted from double-drive reset of population (DDROP), the protocol utilizes simultaneous drives on the transmon and its readout resonator, leveraging the dispersive shift to create a directional process that returns the transmon to the computational subspace. The LRU achieves a 98.4% leakage removal fraction without compromising the computational-state assignment fidelity (99.2%). We combine LRU-enhanced measurement and neural-network decoding to successfully suppress logical error rates in both memory and stability QEC experiments without any post-selection.

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