Disordered Mott Insulator in heavy-light Fermi mixture in optical lattices

Ultracold mixtures of different atomic species have great promise of realizing novel many-body phenomena beyond Hubbard model. In a mixture of femionic atoms with large mass differences, a disordered Mott insulator can be formed as the result of the repulsive interaction between two species. The disorder Mott insulator leads to an incompressible total density of the mixture while the relative density is still compressible. Based on strong-coupling expansion and Monte Carlo calculations, we show that this phase can exist for a broad parameter region for ultracold mixtures confined by a harmonic trap and a three-dimensional optical lattice. The realization of such phase can lead to new ways of quantum control in ultracold mixtures.