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arXiv · 2510.04521

Fast surgery for quantum LDPC codes

Nouédyn Baspin·Lucas Berent·Lawrence Z. Cohen
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Abstract

Quantum LDPC codes promise significant reductions in physical qubit overhead compared with topological codes. However, many existing constructions for performing logical operations come with distance-dependent temporal overheads. We introduce a scheme for performing generalized surgery on quantum LDPC codes using a constant number of rounds of syndrome measurement. The merged code in our scheme is constructed by taking the total complex of the base code and a suitably chosen homomorphic chain complex. We demonstrate the applicability of our scheme on an example multi-cycle code and assess the performance under a phenomenological noise model, showing that fast surgery performs comparably to standard generalized surgery with multiple rounds. Our results pave the way towards fault-tolerant quantum computing with LDPC codes with both low spatial and temporal overheads.

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Nouédyn Baspin, Lucas Berent, Lawrence Z. Cohen. 2025-10-06. Fast surgery for quantum LDPC codes. https://arxiv.org/abs/2510.04521

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