Optimal Pulse Shapes for Cavity-enhanced Brillouin Light Storage

One of the most promising platforms for quantum information processing is using photonics [1]. However, the scaling of photonic quantum network is limited by the fact that many of the operations involved are probabilistic in nature. This scaling problem can be overcome with active synchronisation using quantum memories and temporal multiplexing [2].

A quantum memory is a device capable of storing and retrieving non-classical states of light by coherently mapping onto a stationary state of matter. Many groups worldwide are working on this enabling technology with a number of protocols and physical systems under consideration [3]. Of interest to us, Stimulated Brillouin scattering (SBS) has been used to demonstrate slow light, light storage and quasi-light storage [4]. Physical implementations include on-chip waveguides, fibre and micro-resonators.

We have been investigating cavity-enhanced light storage using SBS in the limit of a strong and constant control field. For both classical and quantum memory, there are two important regimes: weak coupling and strong coupling. In both regimes, we have identified a key figure of merit governing memory performance and have also found a particular pulse shape that optimizes the memory efficiency.