Localization of bosonic atoms by fermionic impurities in a three-dimensional optical lattice.
We observe a localized phase of ultracold bosonic quantum gases in a 3-dimensional optical lattice induced by a small contribution of fermionic atoms acting as impurities in a Fermi-Bose quantum gas mixture. In particular, we study the dependence of this transition on the fermionic (40)K impurity concentration by a comparison to the corresponding superfluid to Mott-insulator transition in a pure bosonic (87)Rb gas and find a significant shift in the transition parameter. The observed shift is larger than expected based on a simple mean-field argument, which indicates that disorder-related effects play a significant role.
Ospelkaus
S
S
Institut für Laserphysik, Luruper Chaussee 149, 22761 Hamburg, Germany.
Ospelkaus
C
C
Wille
O
O
Succo
M
M
Ernst
P
P
Sengstock
K
K
Bongs
K
K