Photon-loss tolerance of the surface-GKP code with anti-photon-loss decoding
Abstract
Photon loss somewhat limits fault-tolerant photonic quantum computing. We investigate its effect on finite-energy Gottesman--Kitaev--Preskill (GKP) states by modeling the pure-loss channel directly. We obtain photon-loss threshold estimates for the surface-GKP code using nearest-lattice-point inner GKP decoding and minimum-weight perfect matching for the outer surface code. For GKP states with ε=0.01 and ε=0.05, corresponding to GKP squeezing of $20$ and 13 dB, the estimated thresholds are γ∗=5.5% (0.24 dB) and γ∗=5.9% (0.26 dB), respectively. We then introduce an anti-photon-loss inner decoder that compensates for the contraction of the measured quadrature. It increases the corresponding threshold estimates to γ∗=9.8% (0.45 dB) and γ∗=6.3% (0.28 dB). Our results highlight the importance of accounting for loss-induced lattice contraction in inner decoding and demonstrate that quadrature compensation enhances the photon-loss tolerance of surface-GKP codes for both high- and moderate-quality GKP states, providing a route toward more photon-loss-robust optical quantum computing.
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BibTeX
@misc{yan2026photonloss,
title = {{Photon-loss tolerance of the surface-GKP code with anti-photon-loss decoding}},
author = {Guan-Ju Yan and Pei-Lin Du and Ke-Min Hu and Jun-Jie He and Yu-Ze Zhu and Xing-Yu Chen and Lin Yang and An-Bang Wu and Hao Tang and Xian-Min Jin},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.00694},
eprint = {2611.00694},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.00694},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Photon-loss tolerance of the surface-GKP code with anti-photon-loss decoding
AU - Guan-Ju Yan
AU - Pei-Lin Du
AU - Ke-Min Hu
AU - Jun-Jie He
AU - Yu-Ze Zhu
AU - Xing-Yu Chen
AU - Lin Yang
AU - An-Bang Wu
AU - Hao Tang
AU - Xian-Min Jin
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.00694
UR - https://arxiv.org/abs/2611.00694
AB - Photon loss somewhat limits fault-tolerant photonic quantum computing. We investigate its effect on finite-energy Gottesman--Kitaev--Preskill (GKP) states by modeling the pure-loss channel directly. We obtain photon-loss threshold estimates for the surface-GKP code using nearest-lattice-point inner GKP decoding and minimum-weight perfect matching for the outer surface code. For GKP states with ε=0.01 and ε=0.05, corresponding to GKP squeezing of $20$ and 13 dB, the estimated thresholds are γ^∗=5.5% (0.24 dB) and γ^∗=5.9% (0.26 dB), respectively. We then introduce an anti-photon-loss inner decoder that compensates for the contraction of the measured quadrature. It increases the corresponding threshold estimates to γ^∗=9.8% (0.45 dB) and γ^∗=6.3% (0.28 dB). Our results highlight the importance of accounting for loss-induced lattice contraction in inner decoding and demonstrate that quadrature compensation enhances the photon-loss tolerance of surface-GKP codes for both high- and moderate-quality GKP states, providing a route toward more photon-loss-robust optical quantum computing.
ER -