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.