Heisenberg Scaling in Many-Body Kinetic Uncertainty Relation via Quantum Feedback
The study investigated achieving Heisenberg scaling (1/N²) in counting precision for many-body systems using quantum feedback on a superradiant spin ensemble. By applying real-time measurement-conditioned feedback, the system is stabilized in a high-activity region where the jump rate scales as O(N²). This converts transient collective enhancement into a resource that improves estimation variance to 1/N², matching fundamental kinetic uncertainty limits.