# Subradiance in Multiply Excited States of Dipole-Coupled V-Type Atoms

## TL;DR

This paper extends the understanding of collective atomic subradiance to multilevel V-type atoms, revealing new dark states that enable long-term storage of multiple photonic excitations through dipole-dipole interactions.

## Contribution

It introduces a theoretical model for multilevel atomic subradiance, demonstrating the existence of dark states that suppress decay in complex atomic ensembles.

## Key findings

- Discovery of non-radiating dark states in multilevel atomic systems
- Long-lived subradiance observed in geometric configurations like triangles and chains
- Probabilistic methods for preparing subradiant states using phase-controlled laser pumping

## Abstract

We generalize the theoretical modeling of collective atomic super- and subradiance to the multilevel case including spontaneous emission from several excited states towards a common ground state. We show that in a closely packed ensemble of $N$ atoms with $N-1$ distinct excited states each, one can find a new class of non-radiating dark states,, which allows for long-term storage of $N-1$ photonic excitations. Via dipole-dipole coupling only a single atom in the ground state is sufficient in order to suppress the decay of all $N-1$ other atoms. By means of some generic geometric configurations, like a triangle of V-type atoms or a chain of atoms with a $J=0 \to J=1$ transition, we study such subradiance including dipole-dipole interactions and show that even at finite distances long lifetimes can be observed. While generally hard to prepare deterministically, we identify various possibilities for a probabilistic preparation via a phase controlled laser pump and decay.