title: Hybrid quantum processors: molecular ensembles as quantum memory for solid state circuits.
abstract: We investigate a hybrid quantum circuit where ensembles of cold polar molecules serve as long-lived quantum memories and optical interfaces for solid state quantum processors. The quantum memory realized by collective spin states (ensemble qubit) is coupled to a high-Q stripline cavity via microwave Raman processes. We show that, for convenient trap-surface distances of a few microm, strong coupling between the cavity and ensemble qubit can be achieved. We discuss basic quantum information protocols, including a swap from the cavity photon bus to the molecular quantum memory, and a deterministic two qubit gate. Finally, we investigate coherence properties of molecular ensemble quantum bits.
authors.affiliation: Institute for Theoretical Physics, University of Innsbruck, and Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Rabl
authors.forename: D
authors.initials: D
authors.lastname: DeMille
authors.forename: J M
authors.initials: JM
authors.lastname: Doyle
authors.forename: M D
authors.initials: MD
authors.lastname: Lukin
authors.forename: R J
authors.initials: RJ
authors.lastname: Schoelkopf
authors.forename: P
authors.initials: P
authors.lastname: Zoller