Abstract: A quantum memory and method are proposed. The quantum memory includes an ensemble of atoms embedded in a storage medium and at least one light source for emitting towards the storage medium first, second and third light pulses, the first light pulse carrying information to be stored. The at least one light source is adapted for emitting second and third light pulses which are such that a photon echo substantially carrying information stored by the first light pulse is emitted by the ensemble of atoms after emission of the third light pulse.

Abstract: A quantum memory and method are proposed. The quantum memory includes an ensemble of atoms embedded in a storage medium and at least one light source for emitting towards the storage medium first, second and third light pulses, the first light pulse carrying information to be stored. The at least one light source is adapted for emitting second and third light pulses which are such that a photon echo substantially carrying information stored by the first light pulse is emitted by the ensemble of atoms after emission of the third light pulse.

Abstract: Via atomic cascade emission, an entangled pair of photons may be generated. A first one of the entangled pair may be ideal for long-distance communication. The other one may be suited for mapping to a long-lived atomic memory. Also, a deterministic single photon may be produced using a feedback system. If the feedback system indicates that an excitation exists in an atomic ensemble, then the atomic ensemble may be hit with a laser to produce the deterministic single photon. Furthermore, gas in the atomic ensemble may be subdivided into independent elements each of which may function as a memory element itself. In addition, dual species matter qubits may be entangled with light. A volume in an atomic ensemble may comprise a first isotope vapor storing a first state of a qubit. The volume may also comprise a second isotope vapor configured to store a second state of the qubit.