Enhancing multiphoton rates with quantum memories

TL;DR

This paper analyzes how quantum memories can significantly increase the production rates of multiphoton states in optical quantum information processing, addressing the limitations of current non-deterministic photon sources.

Contribution

It provides a detailed analysis of the benefits of quantum memories, highlighting the importance of the efficiency and time-bandwidth product for enhancing multiphoton generation.

Findings

Quantum memories can boost multiphoton production rates by many orders of magnitude.

The figure of merit ηB (efficiency times time-bandwidth product) is crucial for performance.

Enhanced rates can mitigate the scalability issues in optical quantum computing.

Abstract

Single photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this `scaling catastrophe'. Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity $\eta B$ as the most important figure of merit in this connection, where $\eta$ and $B$ are the efficiency and time-bandwidth product of the memories, respectively.