Solid state quantum memory using complete absorption and re-emission of photons by tailored and externally controlled inhomogeneous absorption profiles

We present a scheme for storage and retrieval of the quantum state of a single-photon or a weak classical or non-classical optical wave-packet, in a solid-state medium. We describe how the spectral absorption profile of a material such as a rare-earth-ion-doped crystal can be manipulated to efficiently absorb and subsequently reemit a wave-packet, in a photon echo-like process. We discuss how the scheme can be realised experimentally and suggest candidate materials for the storage medium. (c) 2004 Elsevier B.V. All rights reserved.