# Switchable dynamic Rydberg-dressed excitation via a cascaded double electromagnetically induced transparency

## TL;DR

This paper proposes a robust, switchable method for controlling Rydberg excitation in multi-level atomic systems using a cascaded EIT scheme, enabling dynamic, coherent manipulation with enhanced interactions.

## Contribution

It introduces a novel three-step cascaded EIT scheme for dynamic Rydberg dressing control, relaxing laser strength constraints and enhancing interaction effects.

## Key findings

- Achieved switchable Rydberg dressing probability with a control laser.
- Enhanced dressing probability due to atomic interactions.
- Reduced response time in Rydberg excitation control.

## Abstract

Dynamic control of atomic dressing to the highly-excited Rydberg state in multi-level systems has special appeals owing to the development of flexible and precise measurement. In this study we develop an experimentally-accessible proposal to robustly control the dressing probability via a three-step cascaded excitation with double electromagnetically induced transparency (EIT) technique. The system can function as an optical switch where the third addressing laser serving as the control knob can switchably engineer the dressing probability with time. Differing from a conventional two-photon EIT, this novel scheme facilitates the maximal dressing probability determined by a relative strength between two coupling fields, entirely relaxing the absolute values for strong lasers. The collective feature caused by the interactions of a few atoms is also studied leading to an enhanced dressing probability as well as a reduced response time. Our work offers the opportunity to a coherent dynamic control of Rydberg excitation and to realize sizable Rydberg-Rydberg interactions in weakly-driven quantum systems.