Broadband light storage based on superradiance effect in an ensemble of cold atoms *

Superradiance is a collective coherent emission effect that occurs in an initially excited ensemble of emitters due to a constructive interference among their dipole moments without an optical resonator or additional rephasing mechanisms.  In this talk, I will introduce a quantum memory protocol based on this phenomenon of atomic-superradiance in a homogeneously-broadened, optically-dense, cold atomic ensemble. This protocol features non-adiabatic character, making it suitable for efficient storage of short temporal (broadband) pulses.  Along with proof-of-principle experimental demonstrations, I will present our numerical analyses for bandwidth and efficiency scaling of the superradiance-mediated-storage. I will also compare the performance of this scheme with another non-adiabatic broadband memory (Autler-Townes Splitting protocol) that was introduced by our group, and look at recipes and advantages/disadvantages for optimal implementation of each protocol. These results are important for the development of high-performance quantum memories, which are the key ingredients of emerging quantum technologies such as large-scale quantum networks and quantum computers.