# Coulomb anti-blockade in a Rydberg dressed gas

## TL;DR

This paper investigates how Coulomb anti-blockade facilitates plasma formation in Rydberg-dressed gases, revealing correlated Rydberg growth, a transition to Coulomb blockade at high densities, and implications for low-entropy plasma states.

## Contribution

It introduces a rate equation model capturing Coulomb anti-blockade effects and demonstrates the transition from anti-blockade to blockade in ultra-cold plasma formation.

## Key findings

- Plasma forms via Coulomb anti-blockade, with background ions shifting atoms into resonance.
- The rate model accurately reproduces plasma growth and decay.
- Evidence of a crossover from Coulomb anti-blockade to Coulomb blockade at high density.

## Abstract

We perform a comprehensive investigation of the coupling between a Rydberg-dressed atomic gas and an ultra-cold plasma. Using simultaneous time-resolved measurements of both neutral atoms and ions, we show that plasma formation occurs via a Coulomb anti-blockade mechanism, in which background ions DC Stark shift nearby atoms into resonance at specific distances. The result is a highly correlated growth of the Rydberg population that shares some similarities with that previously observed for van der Waals interactions. We show that a rate equation model that couples the laser-driven Rydberg gas to the ultra-cold plasma via a Coulomb anti-blockade mechanism accurately reproduces both the plasma formation and its subsequent decay. Using long-lived high angular momentum states as a probe, we also find evidence of a crossover from Coulomb anti-blockade to Coulomb blockade at high density. As well as shedding light on loss mechanisms in Rydberg-dressed gases, our results open new ways to create low-entropy states in ultra-cold plasmas.