Enhancing bosonic qubit protection by squeezing
Abstract
Bosonic qubits implement error correction by harnessing the high-dimensional Hilbert space of a harmonic oscillator to redundantly encode logical quantum information. Squeezing of quantum states — a cornerstone of precision metrology — redistributes uncertainty between conjugate quadratures to enhance sensitivity in one variable at the expense of the other. In bosonic codes, decoherence can be seen as the environment performing an unwanted measurement on a noise-sensitive quadrature, collapsing superpositions and inducing errors. By redistributing uncertainty to that quadrature, squeezing can be leveraged to reduce the environment’s measurement strength, thereby prolonging coherence. Here, we exploit this insight to implement a squeezing deformation of the simplest bosonic code — the cat qubit — extending the bit-flip time with minimal impact on the phase-flip rate. We observe a dramatic reduction in bit-flip errors, achieving a 160-fold improvement over standard cat qubits and bringing multi-cat architectures closer to fault-tolerant quantum computation. In bosonic codes, decoherence can be seen as the environment performing an unwanted measurement on a noise-sensitive quadrature, collapsing superpositions and inducing errors. Here, the authors show how to use squeezing to further protect bosonic codes from noise, extending the bit-flip times of the cat qubit by two orders of magnitude without reducing phase-flip times.
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BibTeX
@article{rousseau2026enhancing,
title = {{Enhancing bosonic qubit protection by squeezing}},
author = {R. Rousseau and D. Ruiz and E. Albertinale and P. d’Avezac and D. Banys and U. Blandin and N. Bourdaud and G. Campanaro and G. Cardoso and N. Cottet and C. Cullip and S. Deléglise and L. Devanz and A. Devulder and A. Essig and P. Février and A. Gicquel and E. Gouzien and A. Gras and J. Guillaud and E. Gümüş and M. Hallén and A. Jacob and P. Magnard and A. Marquet and S. Miklass and T. Peronnin and S. Polis and F. Rautschke and U. Réglade and J. Roul and J. Stevens and J. Solard and A. Thomas and J.-L. Ville and P. Wan-Fat and R. Lescanne and Z. Leghtas and J. Cohen and S. Jezouin and A. Murani},
journal = {Nature Communications},
year = {2026},
month = oct,
doi = {10.1038/s41467-026-78025-7},
url = {https://www.nature.com/articles/s41467-026-78025-7},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Enhancing bosonic qubit protection by squeezing
AU - R. Rousseau
AU - D. Ruiz
AU - E. Albertinale
AU - P. d’Avezac
AU - D. Banys
AU - U. Blandin
AU - N. Bourdaud
AU - G. Campanaro
AU - G. Cardoso
AU - N. Cottet
AU - C. Cullip
AU - S. Deléglise
AU - L. Devanz
AU - A. Devulder
AU - A. Essig
AU - P. Février
AU - A. Gicquel
AU - E. Gouzien
AU - A. Gras
AU - J. Guillaud
AU - E. Gümüş
AU - M. Hallén
AU - A. Jacob
AU - P. Magnard
AU - A. Marquet
AU - S. Miklass
AU - T. Peronnin
AU - S. Polis
AU - F. Rautschke
AU - U. Réglade
AU - J. Roul
AU - J. Stevens
AU - J. Solard
AU - A. Thomas
AU - J.-L. Ville
AU - P. Wan-Fat
AU - R. Lescanne
AU - Z. Leghtas
AU - J. Cohen
AU - S. Jezouin
AU - A. Murani
PY - 2026
DA - 2026/10/22
JO - Nature Communications
DO - 10.1038/s41467-026-78025-7
UR - https://www.nature.com/articles/s41467-026-78025-7
AB - Bosonic qubits implement error correction by harnessing the high-dimensional Hilbert space of a harmonic oscillator to redundantly encode logical quantum information. Squeezing of quantum states — a cornerstone of precision metrology — redistributes uncertainty between conjugate quadratures to enhance sensitivity in one variable at the expense of the other. In bosonic codes, decoherence can be seen as the environment performing an unwanted measurement on a noise-sensitive quadrature, collapsing superpositions and inducing errors. By redistributing uncertainty to that quadrature, squeezing can be leveraged to reduce the environment’s measurement strength, thereby prolonging coherence. Here, we exploit this insight to implement a squeezing deformation of the simplest bosonic code — the cat qubit — extending the bit-flip time with minimal impact on the phase-flip rate. We observe a dramatic reduction in bit-flip errors, achieving a 160-fold improvement over standard cat qubits and bringing multi-cat architectures closer to fault-tolerant quantum computation. In bosonic codes, decoherence can be seen as the environment performing an unwanted measurement on a noise-sensitive quadrature, collapsing superpositions and inducing errors. Here, the authors show how to use squeezing to further protect bosonic codes from noise, extending the bit-flip times of the cat qubit by two orders of magnitude without reducing phase-flip times.
SN - 2041-1723
ER -