Headwater Control of Antiferromagnetic Domains: Biasing Storage and Certifying Dominance

This work introduces an upstream, write-plus-audit control framework for antiferromagnetic domain systems that moves beyond downstream visibility and treats the domain map S as an explicitly writable and certifiable state variable. Building on recent optics-based SHG domain-imaging advances, the protocol separates “seeing what is already there” from “setting what will be there” by biasing S prior to trusting high-resolution readout. A sign grammar is made explicit: global degeneracy (+n vs. −n) is distinguished from local dominance as a capacity resource under directive drive. The framework elevates axis-aware addressing to avoid eight-point collapse hazards, introduces a three-sign write–audit–read fingerprint (+−+ or −+−) as a noise-resistant control indicator, and enforces falsifiability through flip-only, disable-leakage, withhold-node, and axis-swap tests. Leakage and missingness are handled via ledger separation (zeros remain zeros), overlap yield is logged independently of agreement, and dominance is audited before expensive reconstruction is accepted. The result is a platform-agnostic, falsifiable method for certifying true upstream control of AFM domains—cooperative with state-of-the-art readout, but decisive about control, dominance, and address integrity.