An array of inertial phasor units coupled through a common substrate can exhibit stable collective phase patterns. This paper explores this phenomenon by investigating a closed array–interface–substrate feedback structure. Each array unit has a device-level angular coordinate \(\theta _n\) and produces a phasor output \(e^{i\theta _n}\) . The interface forms products and combinations of these phasor outputs, producing harmonics indexed by integer mode vectors. The substrate processes these harmonic components and returns a modulatory signal to the array. In the case studied here, the returned feedback has gradient form and is generated by a harmonic potential \(V(\theta )\) . This structure leads to a geometric theory of harmonic memory. Memories appear as stable phase-locked periodic solutions, or memory loops, selected by the resonant harmonic structure of \(V\) . Memory recall occurs when the drive parameters, interpreted as attentional control variables, tune the system toward a harmonic channel: resonance selects a latent coherent loop, and the closed dynamics relax toward recurrent activity in the array.
