Quantum information processing with linear optics and atomic ensembles

• Applicant: Professor Jian-Wei Pan, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2004 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5423838

Quantum information science and atom optics are among the most active fields in modern physics. In recent years, many theoretical efforts have been made to combine these two fields. Recent theoretical progresses have shown the in-principle possibility to perform quantum information processing with atomic ensembles. Indeed, how to experimentally exploit atom optics for quantum information applications has become a new focus of research. In this project, we will follow the recent proposals to experimentally investigate the feasibility of implementing quantum information processing with atomic ensembles and linear optics by utilizing the interaction between laser pulses and atomic ensembles. With particular emphasis, we will investigate the potentials of atomic ensembles in the gas phase to build quantum repeaters for long-distance quantum communication, that is, to develop a new technological solution for quantum repeaters making use of the efficient qubit-type entanglement of two cold atomic ensembles by a projective measurement of individual photons by spontaneous Raman processes. On this basis, we will further investigate the advantages of integrating cold atoms an atom chips both to enhance the coherence of atomic ensembles and to enable a miniaturized realization of quantum repeaters. We expect that an implementation of quantum repeaters would open up realistic prospective for quantum communication over long distances. The techniques that will be developed in the experiments would also have many useful applications in various quantum information protocols with atoms and photons.

• DFG Programme: Independent Junior Research Groups