Quantum state transfer from light beams to atomic ensembles

Hanna Krauter

Hanna Krauter, Jacob Friis Sherson, Eugene Simon Polzik

Abstract Quantum teleportation is an interesting feature of quantum mechanics. Entanglement is used as a link between two remote locations to transfer a quantum state without physically sending it – a process that cannot be realized utilizing merely classical tools. Furthermore it has become evident that teleportation is also an important element of future quantum networks and it can be an ingredient for quantum computation. This article reports for the first time the teleportation from light to atoms. In the experiment discussed, the quantum state of a light beam is transferred to an atomic ensemble. The key element of light‐atom entanglement created via a dispersive interaction lays the foundation for the protocol.

Mikhail D. Lukin, Axel André, Matthew D. Eisaman +5 more

We review several ideas for manipulation of quantum information using atomic ensembles and photons and describe some preliminary experiments toward their implementation. In particular, we review a technique that allows for robust transfer of quantum states between light fields and metastable states of matter. Next we discuss the use of Raman scattering to produce robust entanglement of atomic ensembles via realistic (i.e., absorbing) channels. Finally, we present preliminary experimental results related to the implementation of entanglement via Raman scattering. Specifically, we present experimental studies of the intensity fluctuations in resonantly enhanced Raman scattering from a warm 85Rb vapor cell under conditions of EIT. A crossover between the Bose-Einstein and Poisson statistics of Raman light is observed and it is shown that the noise properties of Raman fields can be mirrored in transmitted pump beams.

Hanna Krauter, Jacob Friis Sherson, Kasper Jensen +10 more

Hugues de Riedmatten, Mikael Afzelius

Aurélien Dantan, Nicolas Treps, Alberto Bramati +1 more

We propose a protocol to achieve high fidelity quantum state teleportation of a macroscopic atomic ensemble using a pair of quantum-correlated atomic ensembles. We show how to prepare this pair of ensembles using quasiperfect quantum state transfer processes between light and atoms. Our protocol relies on optical joint measurements of the atomic ensemble states and magnetic feedback reconstruction.