Beyond Pure Dephasing: Quantum Error Correction in Single Molecules Requires Multiple Spins
Abstract
We propose multi-spin molecules as a viable architecture for fault-tolerant quantum computing. To this aim, we introduce a correction protocol handling both diagonal and off-diagonal errors, typically associated with dephasing and relaxation. The scheme is based on a hybrid encoding which combines dephasing-tolerant units suppressing the leading pure dephasing error into a multi-spin molecule implementing a multi-qubit code for residual off-diagonal errors. Our proposal leverages peculiar properties of molecular spins, i.e. the strong hierarchy between different errors and the possibility to engineer multi-spin molecules at the synthetic level. Moreover, it addresses the important issue of the loss of coherences in anharmonic systems subject to off-diagonal errors, which hampers their correction at the single spin level. Thanks to the huge suppression of dephasing by the first-level code, we numerically demonstrate the potential performance of this strategy even with a limited number of spins per logical unit.
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BibTeX
@misc{mezzadri2026beyond,
title = {{Beyond Pure Dephasing: Quantum Error Correction in Single Molecules Requires Multiple Spins}},
author = {Matteo Mezzadri and Silvia Macedonio and Luca Lepori and Emilio Macaluso and Francesco Albarelli and Richard E. P. Winpenny and Alessandro Chiesa and Stefano Carretta},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.03318},
eprint = {2610.03318},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.03318},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Beyond Pure Dephasing: Quantum Error Correction in Single Molecules Requires Multiple Spins
AU - Matteo Mezzadri
AU - Silvia Macedonio
AU - Luca Lepori
AU - Emilio Macaluso
AU - Francesco Albarelli
AU - Richard E. P. Winpenny
AU - Alessandro Chiesa
AU - Stefano Carretta
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2610.03318
UR - https://arxiv.org/abs/2610.03318
AB - We propose multi-spin molecules as a viable architecture for fault-tolerant quantum computing. To this aim, we introduce a correction protocol handling both diagonal and off-diagonal errors, typically associated with dephasing and relaxation. The scheme is based on a hybrid encoding which combines dephasing-tolerant units suppressing the leading pure dephasing error into a multi-spin molecule implementing a multi-qubit code for residual off-diagonal errors. Our proposal leverages peculiar properties of molecular spins, i.e. the strong hierarchy between different errors and the possibility to engineer multi-spin molecules at the synthetic level. Moreover, it addresses the important issue of the loss of coherences in anharmonic systems subject to off-diagonal errors, which hampers their correction at the single spin level. Thanks to the huge suppression of dephasing by the first-level code, we numerically demonstrate the potential performance of this strategy even with a limited number of spins per logical unit.
ER -