تقرير
Directional superradiance in a driven ultracold atomic gas in free-space
| العنوان: | Directional superradiance in a driven ultracold atomic gas in free-space |
|---|---|
| المؤلفون: | Agarwal, Sanaa, Chaparro, Edwin, Barberena, Diego, Orioli, A. Piñeiro, Ferioli, G., Pancaldi, S., Ferrier-Barbut, I., Browaeys, A., Rey, A. M. |
| سنة النشر: | 2024 |
| المجموعة: | Condensed Matter Physics (Other) Quantum Physics |
| مصطلحات موضوعية: | Condensed Matter - Quantum Gases, Physics - Atomic Physics, Quantum Physics |
| الوصف: | Ultra-cold atomic systems are among the most promising platforms that have the potential to shed light on the complex behavior of many-body quantum systems. One prominent example is the case of a dense ensemble illuminated by a strong coherent drive while interacting via dipole-dipole interactions. Despite being subjected to intense investigations, this system retains many open questions. A recent experiment carried out in a pencil-shaped geometry reported measurements that seemed consistent with the emergence of strong collective effects in the form of a ``superradiant'' phase transition in free space, when looking at the light emission properties in the forward direction. Motivated by the experimental observations, we carry out a systematic theoretical analysis of the system's steady-state properties as a function of the driving strength and atom number, $N$. We observe signatures of collective effects in the weak drive regime, which disappear with increasing drive strength as the system evolves into a single-particle-like mixed state comprised of randomly aligned dipoles. Although the steady-state features some similarities to the reported superradiant to normal non-equilibrium transition, also known as cooperative resonance fluorescence, we observe significant qualitative and quantitative differences, including a different scaling of the critical drive parameter (from $N$ to $\sqrt{N}$). We validate the applicability of a mean-field treatment to capture the steady-state dynamics under currently accessible conditions. Furthermore, we develop a simple theoretical model that explains the scaling properties by accounting for interaction-induced inhomogeneous effects and spontaneous emission, which are intrinsic features of interacting disordered arrays in free space. Comment: 25 pages, 19 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2403.15556 |
| رقم الأكسشن: | edsarx.2403.15556 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |