Superradiance in spin-$J$ particles: Effects of multiple levels

TL;DR

This paper extends the theory of superradiance to systems of spin-$j$ particles with multiple energy levels, developing a new formalism to analyze collective effects and potential applications to polar molecules.

Contribution

It introduces a novel approach to model superradiance in multi-level spin-$j$ systems, generalizing Dicke's model and deriving an effective two-body description that accounts for inter-level coherence.

Findings

Superradiance can be modified by multiple energy levels.

The formalism captures cooperative effects in multi-level systems.

Potential application to vibrational states of polar molecules.

Abstract

We study the superradiance dynamics in a dense system of atoms each of which can be generally a spin-$j$ particle with $j$ an arbitrary half-integer. We generalize Dicke's superradiance point of view to multiple-level systems, and compare the results based on a novel approach we have developed in {[}Yelin \textit{et al.}, arXiv:quant-ph/0509184{]}. Using this formalism we derive an effective two-body description that shows cooperative and collective effects for spin-$j$ particles, taking into account the coherence of transitions between different atomic levels. We find that the superradiance, which is well-known as a many-body phenomenon, can also be modified by multiple level effects. We also discuss the feasibility and propose that our approach can be applied to polar molecules, for their vibrational states have multi-level structure which is partially harmonic.