We discuss theoretically quantum interface between light and a spin polarized ensemble of atoms with the spin $⩾1$ based on an off-resonant Raman scattering. We present the spectral theory of the light–atom interaction and show how particular spectral modes of quantum light couple to spatial modes of the extended atomic ensemble. We show how this interaction can be used for quantum memory storage and retrieval and for deterministic entanglement protocols. The proposed protocols are attractive due to their simplicity since they involve just a single pass of light through atoms without the need for elaborate pulse shaping or quantum feedback. As a practically relevant example we consider the interaction of a light pulse with hyperfine components of $D_1$ line of ${}^{87}\mathrm{Rb}$. The quality of the proposed protocols is verified via analytical and numerical analysis.

• Received 16 November 2006

DOI:https://doi.org/10.1103/PhysRevA.75.042326