# Transient dynamics in cavity electromagnetically induced transparency with ion Coulomb crystals

## TL;DR

This paper experimentally studies the transient behavior of an optical cavity interacting with ion Coulomb crystals under electromagnetically induced transparency, demonstrating high control over light-matter interactions at the single-photon level.

## Contribution

It provides the first detailed experimental analysis of EIT dynamics with ion Coulomb crystals in optical cavities, aligning with theoretical models.

## Key findings

- Excellent agreement between experiment and theory.
- Confirmed high degree of control over light-matter interactions.
- Demonstrated EIT at the single-photon level in ion Coulomb crystals.

## Abstract

We experimentally investigate the transient dynamics of an optical cavity field interacting with large ion Coulomb crystals in a situation of electromagnetically induced transparency (EIT). EIT is achieved by injecting a probe field at the single photon level and a more intense control field with opposite circular polarization into the same mode of an optical cavity to couple Zeeman substates of a metastable level in 40Ca+ ions. The EIT interaction dynamics are investigated both in the frequency-domain - by measuring the probe field steady state reflectivity spectrum - and in the time-domain - by measuring the progressive buildup of transparency. The experimental results are observed to be in excellent agreement with theoretical predictions taking into account the inhomogeneity of the control field in the interaction volume, and confirm the high degree of control on light-matter interaction that can be achieved with ion Coulomb crystals in optical cavities.