Enhanced Rydberg Blockade through RF-tuned F\"orster Resonance

TL;DR

This paper introduces a microwave-driven technique to enhance Rydberg atom interactions via F"orster resonance tuning, enabling stronger, longer-range interactions with minimal state shifts, beneficial for quantum computing and simulation.

Contribution

The authors demonstrate a novel RF-tuned F"orster resonance method that significantly enhances Rydberg interactions while minimizing state shifts, improving quantum gate performance.

Findings

Interaction scaling changes from 1/R^6 to 1/R^3

Achieved lower principal quantum number interactions at n=44

Reduced g^{(2)}(0) from 1.0 to 0.38, indicating stronger blockade

Abstract

Enhancing interactions between Rydberg atoms is a key challenge in contemporary quantum technologies. Stronger interactions enable faster Rydberg gates in digital processors and larger entangled states in analog simulation. Achieving the same interaction strength at lower principal quantum number addresses current constraints in available Rabi frequency and field sensitivity in large scale tweezer or cavity QED experiments. Here, we demonstrate a new technique using AC Stark shifts from a microwave drive to tune into a F\"orster resonance, thereby modifying the interaction scaling with distance from $1/R^6$ to $1/R^3$. We validate enhanced Rydberg interactions (in strength and range) by probing cavity Rydberg polariton blockade at $n=44$ in $^{87}$Rb, improving from $g^{(2)}(0) = 1.0 (1)$ in the Van-der-Waals regime to $g^{(2)}(0) = 0.38 (1)$ in the dipolar regime on the F\"orster resonance. Importantly, our technique allows minimal shifts of the original Rydberg state, suppressing detuning errors in gate protocols while maintaining quadratic insensitivity to DC electric fields.