Abstract

When a physical system resolves a competition (a laser selecting a mode, a condensate occupying a spin state, an array of Rydberg atoms relaxing under blockade) the winning state carries a high-dimensional signature far richer than the winner’s identity. These signatures are routinely discarded. I will argue that they should not be. I will survey three families of physical selectors: spatial photonic Ising machines, polariton condensate networks, and polychronous wave computers, showing how driven-dissipative competition naturally implements winner-take-all routing. These systems share a structural pattern: competition produces both a discrete outcome and a continuous post-selection state. Attractor-keyed memory (AKM) formalises this observation. If the post-selection signatures are repeatable and linearly independent across routes, a single linear decoder compiled from calibration data maps them to arbitrary payloads, merging selection and memory access into one physical event. A single SVD certifies capability for any downstream task before it is chosen, and runtime error separates into two independently diagnosable channels with distinct physical remedies. I present the first hardware AKM test: a five-atom Rydberg cell on QuEra’s Aquila processor, where blockade-mediated competition selects a route and van der Waals interactions write a route-conditioned excitation fingerprint onto neighbouring atoms. The fingerprints survive on hardware, and a regularised decoder retrieves payloads below the route-blind baseline. The broader message is a design principle: physical selectors should be engineered not only to choose a winner, but to emit decodable post-selection signatures.