Directional Excitation Transport and Microwave Detection in Cold Rydberg Experiments*

Rydberg facilitation enables intriguing dynamics and applications in cold atom experiments. We propose an experimental scheme to achieve directional transport of Rydberg excitations and entangled states in an atomic array with unequal spacing. By modulating the detuning of global laser fields to compensate for the distance-dependent energy shifts induced by Rydberg-Rydberg interactions, our method enables controlled excitation flow along arbitrary trajectories. Theoretical simulations indicate that, under realistic experimental conditions, our scheme is robust against positional disorder and preserves entanglement during transport. Additionally, we present an experimental work for detecting microwave signals in an atomic ensemble. The strong dipole coupling between Rydberg states enhances huge sensitivity to microwave fields. By coupling to nearby states, Rydberg electromagnetically induced transparency (EIT) signal is modified and enables precise microwave sensing.