Initialization masks overcome decoding obstructions in compressed QAOA

arXiv:2611.10588v1 Announce Type: new Abstract: In compressed quantum optimization, a variational state is converted into a classical assignment by decoding noncommuting observables. We show that this step creates structural restrictions that changing the initialization can remove, even when increasing circuit depth cannot. For an explicit infinite family of connected cubic graphs on $n=3r$ vertices, with a fixed Pauli encoding and deterministic sign decoder, every all-plus QAOA circuit has cut at most $2r$, at every finite depth and every real angle sequence. A uniform signed product-state mask at fixed depth-one angles has expected cut $13r/4$, an additive advantage $5n/12$; an infinite subfamily admits an optimal mask.