SpiderCSS: Scalable Fault-Tolerant CSS State Preparation
Abstract
Fault-tolerant preparation of logical states is a critical primitive for the realization of large-scale fault-tolerant quantum computing. This paper introduces SpiderCSS, a scalable compilation pipeline that generates highly-optimized, fault-tolerant state preparation circuits for arbitrary Calderbank-Shor-Steane (CSS) codes. Starting from an idealized specification of a CSS state, we use the ZX-calculus and fault-equivalent rewrites to construct a diagram that prepares the given state while preserving the fault tolerance of the initial ideal ZX-diagram. From this diagram, SpiderCSS constructs a fault-tolerant CSS-state preparation circuit using a modular construction that is CNOT-minimal both within each component and also in the way these components are connected together. By only using fault-equivalent rewrites, the final circuit is provably fault-tolerant without needing expensive verification. Monte Carlo simulations across a variety of CSS codes up to distance 15 show that SpiderCSS scales efficiently and constructs circuits with substantially reduced depth and qubit footprint compared to existing scalable and heuristic methods, while simultaneously achieving an average decrease of 33.7% in logical error rate and an increase of 9.5% in acceptance rate.
Related
- Two-Layer Verification for Fault-Tolerant Magic-State Preparation in High-Rate Quantum Codes
- Fault-tolerant resource estimation for ground-state preparation via Lindblad simulation
- Fault-Tolerant Logical Operations and Efficient State Preparation in Modular Quantum Architectures with Noisy Interfaces
- Fast verification of fault tolerant magic state preparation circuits with the CNOT + T gate set
- Extremely Low-Cost Magic State Preparation toward Fault-Tolerant Quantum Computing
BibTeX
@misc{poor2026spidercss,
title = {{SpiderCSS: Scalable Fault-Tolerant CSS State Preparation}},
author = {Boldizsár Poór and Andrey Boris Khesin and Sarah Meng Li and Benjamin Rodatz and John van de Wetering and Richie Yeung},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.03714},
eprint = {2610.03714},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.03714},
}
RIS
TY - UNPB
TI - SpiderCSS: Scalable Fault-Tolerant CSS State Preparation
AU - Boldizsár Poór
AU - Andrey Boris Khesin
AU - Sarah Meng Li
AU - Benjamin Rodatz
AU - John van de Wetering
AU - Richie Yeung
PY - 2026
DA - 2026/10/02
PB - arXiv
DO - 10.48550/arxiv.2610.03714
UR - https://arxiv.org/abs/2610.03714
AB - Fault-tolerant preparation of logical states is a critical primitive for the realization of large-scale fault-tolerant quantum computing. This paper introduces SpiderCSS, a scalable compilation pipeline that generates highly-optimized, fault-tolerant state preparation circuits for arbitrary Calderbank-Shor-Steane (CSS) codes. Starting from an idealized specification of a CSS state, we use the ZX-calculus and fault-equivalent rewrites to construct a diagram that prepares the given state while preserving the fault tolerance of the initial ideal ZX-diagram. From this diagram, SpiderCSS constructs a fault-tolerant CSS-state preparation circuit using a modular construction that is CNOT-minimal both within each component and also in the way these components are connected together. By only using fault-equivalent rewrites, the final circuit is provably fault-tolerant without needing expensive verification. Monte Carlo simulations across a variety of CSS codes up to distance 15 show that SpiderCSS scales efficiently and constructs circuits with substantially reduced depth and qubit footprint compared to existing scalable and heuristic methods, while simultaneously achieving an average decrease of 33.7% in logical error rate and an increase of 9.5% in acceptance rate.
ER -