# Quantum engineering of photon states with entangled atomic ensembles

## TL;DR

This paper introduces a cavity-free, deterministic method for generating single and entangled photons using entangled atomic ensembles, enabling versatile photonic state production with potential applications in quantum communication.

## Contribution

It presents a novel scheme leveraging collective atomic entanglement for photon generation, adaptable to various atomic systems, without the need for optical cavities.

## Key findings

- Feasible implementation in ion traps, optical lattices, and room-temperature cells.
- Deterministic photon emission triggered by laser pulses.
- Ability to produce diverse entangled photonic states.

## Abstract

We propose and analyze a new method to produce single and entangled photons which does not require cavities. It relies on the collective enhancement of light emission as a consequence of the presence of entanglement in atomic ensembles. Light emission is triggered by a laser pulse, and therefore our scheme is deterministic. Furthermore, it allows one to produce a variety of photonic entangled states by first preparing certain atomic states using simple sequences of quantum gates. We analyze the feasibility of our scheme, and particularize it to: ions in linear traps, atoms in optical lattices, and in cells at room temperature.