Multiband spectroscopy of ultracold fermions: observation of reduced tunneling in attractive Bose-Fermi mixtures.
We perform a detailed experimental study of the band excitations and tunneling properties of ultracold fermions in optical lattices. Employing a novel multiband spectroscopy for fermionic atoms, we can measure the full band structure and tunneling energy with high accuracy. In an attractive Bose-Fermi mixture we observe a significant reduction of the fermionic tunneling energy, which depends on the relative atom numbers. We attribute this to an interaction-induced increase of the lattice depth due to the self-trapping of the atoms.
Institut für Laser-Physik, Universität Hamburg, Germany.
J
J
Heinze
S
S
Götze
J S
JS
Krauser
B
B
Hundt
N
N
Fläschner
D-S
DS
Lühmann
C
C
Becker
K
K
Sengstock