Collective decay for trapped circular Rydberg atoms at finite temperature

01.04.2026 bis 31.12.2026

This project investigates the collective decay dynamics of trapped circular Rydberg atoms at finite temperature, with the aim of enabling longer coherence times and scalable quantum technologies. Circular Rydberg states offer exceptionally long intrinsic lifetimes, but at room temperature their performance is limited by black‑body‑induced transitions. Recent experiments have demonstrated that placing single circular Rydberg atoms inside a capacitor suppresses relevant electromagnetic modes, achieving record lifetimes without cryogenic cooling. Building on this progress, the project explores how ensembles of such atoms behave when dipole–dipole interactions and cavity-induced modifications jointly shape their decay processes. Theoretical work will develop a first‑principles quantum master equation capturing collective effects at zero and finite temperatures, including superradiance, subradiance, and correlated black‑body‑driven transitions—an uncharted regime. These insights will directly guide ongoing experiments in Stuttgart, where few‑ and many‑atom circular Rydberg arrays are being realized inside capacitor structures. By tuning the principal quantum number, the experimental team will access a continuum from free-space-like to cavity-dominated environments, enabling detailed studies of correlated decay, metastability, and emergent dynamics. The project strengthens collaboration between theory and experiment across IQST institutions and contributes foundational work to future initiatives such as the planned DFG Collaborative Research Center on robust quantum phenomena.