The possibility to independently tune the interspecies interactions and the tunneling probability among neighboring lattice sites makes our mixture perfectly suitable to this purpose.
We have already obtained a double Mott insulator phase for both Rb and K. This has been realized in a full phase separated system, mimicking a zero interaction among the two clouds. Our aim is to exploit the predicted low field interspecies Feshbach resonances (that still have to be observed) to tune the interactions among the two species during the transition from the superfluid to the Mott phase.
The possibility to tune the interactions, and the different masses of the two elements will in principle allow to distiguish the transition points for Rb and K. This features gives the chance to realize a compound system formed by localized atoms in the insulating phase, acting as a matter grating, and a superfluid cloud, represented by the atomic specie that has not still crossed the transition. The interaction and the dynamics between these two different systems can then be deeply investigated.
Topological issues, driven by the variable interaction among the two bosonic species, can eventually be studied, with a particular interest in the double Mott insulator phase.