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arXiv · 2511.06108

Squeezed-vacuum bosonic codes

Nir Gutman·Eliya Blumenthal·Shay Hacohen-Gourgy·Ariel Orda·Ido Kaminer
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Abstract

We introduce a family of bosonic quantum error-correcting codes built as a rotation-symmetric superposition of squeezed vacuum states, which promise protection against both loss and dephasing noise channels. The robustness of these "squeezed-vacuum codes" arises from being arranged at evenly spaced angles in phase-space, and simultaneously in evenly spaced photon-number support $n \equiv {2k} \! \pmod {2m}$. We present simple preparation circuits: a two-legged code using a Hadamard-conditional-squeezing-Hadamard sequence on an ancilla qubit, and for general "$m$-legged" codewords using sequences of conditional rotations. The performance of these codes is evaluated against loss and dephasing noises using the Knill-Laflamme violation function and benchmarked against cat codes. As the number $m$ of squeezed-vacuum states in a code increases, the code exhibits improved loss tolerance at the cost of higher dephasing sensitivity. We outline implementations in circuit QED and trapped-ion platforms, where high-fidelity Gaussian operations and conditional controls are available or under active development. These results help establish squeezed-vacuum codes as practical, hardware-ready, members of the bosonic codes class.

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Nir Gutman, Eliya Blumenthal, Shay Hacohen-Gourgy, Ariel Orda, Ido Kaminer. 2025-11-08. Squeezed-vacuum bosonic codes. https://doi.org/10.1002/apxr.202600007

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