Cavity enhanced storage - preparing for high efficiency quantum memories

TL;DR

This paper demonstrates a cavity-assisted quantum memory that significantly enhances efficiency and reduces cavity mode spacing and line-width by several orders of magnitude, leveraging absorption engineering and slow light effects.

Contribution

The study provides the first experimental demonstration of large-scale cavity mode spacing and line-width reduction due to slow light effects in quantum memories.

Findings

20-fold increase in quantum memory efficiency

Reduction of cavity mode spacing and line-width by over three orders of magnitude

Observation of strong dispersion effects from absorption engineering

Abstract

Cavity assisted quantum memory storage has been proposed [PRA 82, 022310 (2010), PRA 82, 022311 (2010)] for creating efficient (close to unity) quantum memories using weakly absorbing materials. Using this approach we experimentally demonstrate a significant (about 20-fold) enhancement in quantum memory efficiency compared to the no cavity case. A strong dispersion originating from absorption engineering inside the cavity was observed, which directly affect the cavity line-width. A more than 3 orders of magnitude reduction of cavity mode spacing and cavity line-width from GHz to MHz was observed. We are not aware of any previous observation of several orders of magnitudes cavity mode spacing and cavity line-width reduction due to slow light effects.