B. Deh

Quantum-Degenerate Mixture of Fermionic Lithium and Bosonic Rubidium Gases

We report on the observation of sympathetic cooling of a cloud of fermionic 6Li atoms which are thermally coupled to evaporatively cooled bosonic 87Rb. Using this technique we obtain a mixture of quantum-degenerate gases, where the Rb cloud is colder than the critical temperature for Bose-Einstein condensation and the Li cloud is colder than the Fermi temperature. From measurements of the thermalization velocity we estimate the interspecies s-wave triplet scattering length |amx|=20(+9)(-6)aB. We found that the presence of residual rubidium atoms in the |2, 1> and the |1, -1> Zeeman substates gives rise to important losses due to inelastic collisions.

Highly versatile atomic micro traps generated by multifrequency magnetic field modulation

We propose the realization of custom-designed adiabatic potentials for cold atoms based on multimode radio frequency radiation in combination with static inhomogeneous magnetic fields. For example, the use of radio frequency combs gives rise to periodic potentials acting as gratings for cold atoms. In strong magnetic field gradients, the lattice constant can be well below 1 µm. By changing the frequencies of the comb in time the gratings can easily be propagated in space, which may prove useful for Bragg scattering atomic matter waves. Furthermore, almost arbitrarily shaped potentials are possible such as disordered potentials on a scale of several 100 nm or lattices with a spatially varying lattice constant. The potentials can be made state selective and, in the case of atomic mixtures, also species selective. This opens new perspectives for generating tailored quantum systems based on ultracold single atoms or degenerate atomic and molecular quantum gases.

Feshbach resonances in mixtures of ultracold Li 6 and Rb 87 gases

We report on the observation of two Feshbach resonances in collisions between ultracold

Phase-sensitive detection of bragg scattering at 1D optical lattices.

^{6}\mathrm{Li}

Ultracold thermalization ofLi7andRb87

and

The Collective Atomic Recoil Laser

^{87}\mathrm{Rb}

In situ Ramsey interferometry and diffraction echo with an atomic Fermi gas

atoms in their respective hyperfine ground states

Feshbach resonances in an ultracold 7Li and 87Rb mixture

\ensuremath{\mid}F,{m}_{F}⟩=\ensuremath{\mid}1∕2,1∕2⟩

Ultracold thermalization of 7Li and 87Rb

and \ensuremath{\mid}1,1⟩. The resonances show up as trap losses for the

Ultracold thermalization of {sup 7}Li and {sup 87}Rb

^{6}\mathrm{Li}