The effects of high optical depth phenomena, such as superradiance, are investigated in potential quantum memory materials. The results may have relevance for several schemes, including CRIB, AFC and EIT-based quantum memories, which are based on using ensembles as storage media. It is shown that strong superradiant effects, manifested as decay rates larger than 1/T2*, are present even for moderate values of alphaL < 5, and increases as a function of alphaL. For even higher alphaL, effects like off-resonant slow light is demonstrated and discussed, and finally, the efficiency of time-reversed optimized input pulses are tested. A maximum retrieval efficiency of ~20% is reached, and agreement with the theoretically expected result is discussed.
@article{arxiv.0904.4621,
title = {Experimental superradiance and slow light effects for quantum memories},
author = {Andreas Walther and Atia Amari and Stefan Kröll and Alexey Kalachev},
journal= {arXiv preprint arXiv:0904.4621},
year = {2009}
}