  We present a quantum multi-modal treatment describing Electromagnetically
Induced Transparency (EIT) as a mechanism for storing continuous variable
quantum information in light fields. Taking into account the atomic noise and
decoherences of realistic experiments, we model numerically the propagation,
storage, and readout of signals contained in the sideband amplitude and phase
quadratures of a light pulse. An analytical treatment of the effects predicted
by this more sophisticated model is then presented. Finally, we use quantum
information benchmarks to examine the properties of the EIT-based memory and
show the parameters needed to operate beyond the quantum limit.
