The understanding of light matter interfaces is the crucial ingredient in any attempt to link the nodes of a quantum network. Although being very successful to lay the foundations for the building blocks of future quantum networks, high finesse cavity QED is facing technological limitations when it comes to scaling the networks up to large sizes. Therefore alternative routes to map nonclassical states of matter to light fields are of fundamental interest. In this project we concentrate on the interface between light and ensembles of atoms prepared in nonclassical collective quantum states. Due to the collective nature of the atom light interaction the coupling between the ensemble and individual light modes can be strong. Here the field enhancement in cavity QED is replaced by the collectivity of the radiating dipoles. We will explore the fundamental limits and the full theoretical framework of such ensembles and various ways to prepare them. Microfabricated thermal vapor cells, which can be prepared in a scalable way are a promising technological platform for our approach. Ultracold atoms are also studied to understand the underlying processes. To prepare relevant collective quantum states strong interactions in quantum gases, the Rydberg blockade or projective methods are used. The new expertise emerging from our project will provide progress in Information and Communication Technology (ICT).
|Coordinator: Laboratorio Europeo Spettroscopia Non-lineare||LENS||Italy|
|Gottfried Wilhelm Leibniz Universität Hannover||LUH||Germany|