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  • Open Access

Protocol for purifying noisy preparation and measurements of qubits

Jaemin Kim1,2, Seungchan Seo1, Jiyoung Yun1, Benjamin Lienhard3,4, and Joonwoo Bae1,*

  • *Contact author: joonwoo.bae@kaist.ac.kr
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Phys. Rev. Research 8, 023347 – Published 26 June, 2026

DOI: https://doi.org/10.1103/z6pg-m3q6

Abstract

Noise affecting qubit preparation and measurements accounts for a significant fraction of errors in quantum information processing. This is especially critical in tasks like variational quantum algorithms, quantum error correction, and entanglement distribution through repeaters. In this work, we present a protocol to purify noisy state preparation and measurement (SPAM), effectively suppressing these errors to an arbitrarily low level. For instance, in a realistic scenario where qubits contain error rates around 0.05 in both preparation and measurement, the protocol can suppress error rates up to 10−3 with two ancillas and 10−6 with four ancillas. We show how to distill error-free SPAM by repeating noisy SPAMs. The protocol is also feasible with superconducting qubits. We envisage that our results can be used to realize quantum information tasks in computing and communication with negligible SPAM errors.

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Phys. Rev. Research 8, 023347– Published 26 June, 2026
  • Received 21 August 2025
  • Accepted 4 June 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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