Hybrid Quantum Processors: Molecular Ensembles as Quantum Memory for Solid State Circuits
Peter Rabl, David P. DeMille, John M. Doyle, Mikhail D. Lukin, Robert J. Schoelkopf, P. Zoller · Physical Review Letters · 2006
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.