MERLIN SCIENCE — A Syndrome-Extraction Framework for Distributed Lattice Surgery on Arb — E8 Intelligence Research

# MERLIN SCIENCE NARRATION The finding: we've solved the hook-error problem in modular quantum computing by splitting merged surface code layouts at a seam using two-qubit measurements mediated through Bell pairs, which keeps logical error rates stable even when link errors run a hundred times noisier than bulk errors. Here's the context. Modular quantum computing scales by linking independent quantum processors through noisy inter-module gates. When you perform lattice surgery to merge surface code patches, you create configurations where errors can propagate in multiple directions, especially hook errors that kill your fault distance. Existing methods either bloat your syndrome extraction circuits or let those errors corrupt the bulk code itself. You're stuck choosing between two bad options. What we did: we constructed a seam that acts as a barrier. When you merge rotated surface codes, instead of letting weight-four stabilizers span the boundary unsupervised, we split them into Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com