Abstract

Quantum physics is currently confined to separate Œworlds¹ ­ separated by deserts of classical physics. One of the main challenges is to link different quantum systems to each other /and/ at the same time preserve the quantum nature over the link; to build /quantum interconnects/between the different domains. Coherent micro manipulation in integrated quantum optical devices, AtomChips is an ideal platform to implement such quantum interconnects. The talk will focus in two aspects of the basic physics required:

(1) Coherent manipulation of Atoms on AtomChips: Employing RF induced adiabatic potentials enables coherent  manipulation of trapped matter waves with high precision. Using our exceptionally smooth AtomChip potentials we study 1d condensates at strong transversal confinement (>10kHz) and extreme aspect ratio up to 10000, which can be coherently split along their long axis. The interference pattern itself is sensitive probe of the order parameter in  the 1d quantum gas and allows detailed studies of its coherence properties.

(2) Raman transition in atomic ensembles offer a robust physical system to connect photons (flying qubits) to atoms (quantum memory). The talk will present our recent experiments connecting photons to atomic ensembles. The first illustrates limitations due to collisional decoherence in thermal ensembles, The other three illustrate the versatility of ultra-cold atoms, by describing a heralded single  photon source, entangling two independently created single photons, anda demonstration of memory built in teleportation of an photonic qubit.