Atom-photon Quantum Interface for Quantum Information

Sébastien Tanzilli, Wolfgang Tittel, M. Halder +4 more

Mohammad Hafezi, Z. Kim, S. L. Rolston +3 more

A complete physical approach to quantum information requires a robust interface among flying qubits, long-lifetime memory, and computational qubits. Here we present a unified interface for microwave and optical photons, potentially connecting engineerable quantum devices such as superconducting qubits at long distances through optical photons. Our approach uses an ultracold ensemble of atoms for two purposes: quantum memory and to transduce excitations between the two frequency domains. Using coherent control techniques, we examine an approach for converting and storing quantum information between microwave photons in superconducting resonators, ensembles of ultracold atoms, and optical photons, as well as a method for transferring information between two resonators.

Pieter Kok, Brendon W. Lovett

Sébastien Tanzilli, Wolfgang Tittel, Hugo Zbinden +3 more

The experiment performed aims to transfer the quantum information (QI) carried by "telecom photons" at 1310 nm to "visible photons". This is a necessary step to realize a quantum interface between photons and atoms. To this end, in the most general case, entanglement produced by parametric down-conversion is preserved when submitting one photon out of an entangled pair to a wavelength up-conversion process (i.e. sum frequency generation SFG) in a nonlinear crystal.

Matteo Cristiani, T. Valenzuela, Jürgen Eschner

We have designed a set-up for realizing single atom -single photon interfaces as a resource for quantum optics, quantum computing, and quantum information experiments. The highly modular and versatile experimental set-up will allow us to implement into the system the most recent technology with only minor changes.