Gaussification of quantum states of traveling light beams in atomic memory

TL;DR

This paper presents a protocol for Gaussifying quantum states of traveling light beams using atomic quantum memory and quantum non-demolition interactions, enabling entanglement and purification of non-Gaussian states.

Contribution

The proposed scheme introduces a novel method for Gaussification and entanglement of light states via a logarithmic scaling coupling in atomic memories.

Findings

Protocol enables entanglement of distant atomic ensembles.

Efficient Gaussification of noisy non-Gaussian states.

Coupling strength scales logarithmically with the number of modes.

Abstract

We propose and investigate a protocol for Gaussification of quantum states of traveling light beams in an atomic quantum memory that couples to light via quantum non-demolition interaction. The protocol relies on a periodic switching between two different QND couplings and the total coupling strength scales only logarithmically with number of Gaussified light modes. The present scheme can be used to prepare entangled states of two distant atomic ensembles and to purify and Gaussify noisy non-Gaussian entangled states of light while simultaneously storing the purified state in atomic memories.