München 2004 – scientific programme

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Q: Quantenoptik und Photonik

Q 52: Postdeadline

Q 52.7: Talk

Thursday, March 25, 2004, 21:00–21:10, HS 225

Atom Interferometry with Trapped Fermi Gases — •Herwig Ott, Estafania de Mirandes, Francesca Ferlaino, Giacomo Roati, Giovanni Modugno, and Massimo Inguscio — LENS and Dipartimento di Fisica, Università di Firenze, and INFM, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy

We present the realization of an atomic interferometer by trapping a non interacting Fermi gas of ⁴⁰K atoms in an optical lattice (λ=873 nm) aligned along gravity [1]. The single particle interference arises from the coherent superposition of the localized eigenstates of the lattice and leads to Bloch oscillations of the atoms. We can follow more than 100 oscillations and from the measured Bloch oscillation period T=2h/mgλ we can extract the gravitational acceleration g with a precision of 100 ppm. An identical experiment using a Bose Einstein condensate of ⁸⁷Rb atoms reveals a strongly reduced visibility of the fringes. This is due to the interaction which destroys the interference after a few oscillations. Our experiment proofs the superiorness of non interacting fermions with respect to interacting bosons in the direction of realizing precision interferometry with ultracold trapped atoms.

[1] G. Roati, E. de Mirandes, F. Ferlaino, H. Ott, G. Modugno, and M. Inguscio, cond-mat/0402328.