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arXiv · 2207.07058

Optimising the Efficiency of a Quantum Memory based on Rephased Amplified Spontaneous Emission

Charlotte K. Duda·Kate R. Ferguson·Rose L. Ahlefeldt·Morgan P. Hedges·Matthew J. Sellars
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Abstract

We studied the recall efficiency as a function of optical depth of rephased amplified spontaneous emission (RASE), a protocol for generating entangled light. The experiments were performed on the $^{3}\! H_{4}$ $\rightarrow$ $^{1}\! D_{2}$ transition in the rare-earth doped crystal Pr$^{3+}$:Y$_{2}$SiO$_{5}$, using a four-level echo sequence between four hyperfine levels to rephase the emission. Rephased emission was observed for optical depths in the range of $\alpha L$ = 0.8 to 2.0 with a maximum rephasing efficiency of 14 % observed while incorporating spin storage. This efficiency is a significant improvement over the previously reported non-classical result but is well short of the predicted efficiency. We discuss the possible mechanisms limiting the protocol's performance, and suggest ways to overcome these limits.

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Charlotte K. Duda, Kate R. Ferguson, Rose L. Ahlefeldt, Morgan P. Hedges, Matthew J. Sellars. 2022-07-14. Optimising the Efficiency of a Quantum Memory based on Rephased Amplified Spontaneous Emission. https://doi.org/10.1103/physreva.107.l030602

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