Iterative tailoring of optical quantum states with homodyne measurements

TL;DR

This paper introduces a new protocol for generating and expanding arbitrary optical quantum states using iterative homodyne measurements and coherent additions, potentially improving success probabilities over existing methods.

Contribution

The authors propose a novel iterative protocol leveraging quantum memories for the growth of arbitrary optical quantum states, enhancing efficiency compared to prior approaches.

Findings

Protocol enables growth of arbitrary states with higher success probability.

Uses coherent adjunctions of simple superposition states.

Leverages quantum memories for improved performance.

Abstract

As they can travel long distances, free space optical quantum states are good candidates for carrying information in quantum information technology protocols. These states, however, are often complex to produce and require protocols whose success probability drops quickly with an increase of the mean photon number. Here we propose a new protocol for the generation and growth of arbitrary states, based on one by one coherent adjunctions of the simple state superposition $\alpha | 0 > +\beta | 1 >$. Due to the nature of the protocol, that allows for the use of quantum memories, it can outperform existing protocols.