A dissipation-induced superradiant transition in a strontium cavity-QED system

Driven-dissipative many-body systems are ubiquitous in nature and a fundamental resource for quantum technologies. However, they are also complex and hard to model since they cannot be described by the standard tools in equilibrium statistical mechanics. Probing non-equilibrium critical phenomena in pristine setups can illuminate new perspectives on such systems. Here we use an ensemble of cold $^{88}$Sr atoms coupled to a driven high-finesse cavity to study the cooperative resonance fluorescence (CRF) model, a classic driven-dissipative model describing coherently driven dipoles superradiantly emitting light. We observe its non-equilibrium phase diagram characterized by a second-order phase transition. Below a critical drive strength, the atoms quickly reach the so-called superradiant steady-state featuring a macroscopic dipole moment; above the critical point, the atoms undergo persistent Rabi-like oscillations. At longer times, spontaneous emission transforms the second-order transit..., , , # A dissipation-induced superradiant transition in a strontium cavity-QED system

[https://doi.org/10.5061/dryad.j6q573nrb](https://doi.org/10.5061/dryad.j6q573nrb)

## Description of the data and file structure

Files are named according to the following naming convention: fig`ASSOCIATED SUBFIGURE.csv`. See the explanation below:

`[ASSOCIATED SUBFIGURE]` references the subfigure of the manuscript where the data is plotted. This repository contains data from `fig2`, `fig3`, `fig4`, and `fig5`, which are the four figures containing experimental data. All of these figures contain sub-panels which are labeled alphabetically. For example, data from Fig. 2, panel c is referenced by `fig2c`.

Data in each file is separated into columns. They represent x, y-coordinate value of each data point or corresponding error bars. They are labeled according to the following naming convention: `[PARAMETER]_[COORDINATE/ERRORBAR]`. See the explanation below:

`[PARAMETER]` refers to the parameter distingu...,