title: Entanglement interferometry for precision measurement of atomic scattering properties.
abstract: We report on a matter wave interferometer realized with entangled pairs of trapped 87Rb atoms. Each pair of atoms is confined at a single site of an optical lattice potential. The interferometer is realized by first creating a coherent spin superposition of the two atoms and then tuning the interstate scattering length via a Feshbach resonance. The selective change of the interstate scattering length leads to an entanglement dynamics of the two-particle state that can be detected in a Ramsey interference experiment. This entanglement dynamics is employed for a precision measurement of atomic interaction parameters. Furthermore, the interferometer allows us to separate lattice sites with one or two atoms in a nondestructive way.
authors.affiliation: Ludwig-Maximilians-Universität, Schellingstrasse 4/III, 80799 Munich, Germany. widera@uni-mainz.de
authors.forename: Artur
authors.initials: A
authors.lastname: Widera
authors.forename: Olaf
authors.initials: O
authors.lastname: Mandel
authors.forename: Markus
authors.initials: M
authors.lastname: Greiner
authors.forename: Susanne
authors.initials: S
authors.lastname: Kreim
authors.forename: Theodor W
authors.initials: TW
authors.lastname: Hänsch
authors.forename: Immanuel
authors.initials: I
authors.lastname: Bloch