This study investigates the influence of geomagnetic activity on the stability of human sleep architecture using two independent sleep datasets (18 nights and 9 nights). We introduce the Architecture Entropy Index (AEI) and propose a formal REM Gating Controller model to quantify how external geomagnetic perturbations interact with intrinsic sleep-state dynamics. Our results demonstrate a pronounced increase in the probability of direct transitions from deep sleep to wakefulness under high auroral electrojet (AE) activity, alongside a reproducible ~35-minute temporal lag between geomagnetic fluctuations and cortical network reorganization. These findings indicate that human sleep is not a closed homeostatic system but a dynamically modulated process sensitive to external electromagnetic forcing.