Atom Interferometer Gravimeter — Spacetime Diagram

This is the 2D counterpart to the 3D atom-interferometer gravimeter: instead of a perspective scene, it draws the physics the way real papers plot it. A space-time worldline diagram shows the atom cloud's two momentum-state paths opening and closing in a "diamond" as the π/2–π–π/2 Raman pulse sequence runs, a phasor shows the accumulated quantum phase Δφ = k_effgT² as a rotating vector, and a live fringe-scan panel plots the exact cosine probability curve P(|e⟩)=½[1−cos(Δφ)] — press "Scan g" to sweep gravity and watch single-shot Monte-Carlo measurements build up the same fringe a real gravimeter would record.