  We analyze multipartite entanglement between atomic ensembles within quantum
matter-light interfaces. In our proposal, a polarized light beam crosses
sequentially several polarized atomic ensembles impinging on each of them at a
given angle \alpha_i. These angles are crucial parameters for shaping the
entanglement since they are directly connected to the appropriate combinations
of the collective atomic spins that are squeezed. We exploit such scheme to go
beyond the pure state paradigm proposing realistic experimental settings to
address multipartite mixed state entanglement in continuous variables.
