Theoretical investigation of correlated fermions on optical lattice with spin-dependent disorder

Andrew Fu Wah Ho

Karol Makuch, Jan Skolimowski, P B Chakraborty +2 more

Motivated by the rapidly growing possibilities for experiments with ultracold atoms in optical lattices, we investigate the thermodynamic properties of correlated lattice fermions in the presence of an external spin-dependent random potential. The corresponding model, a Hubbard model with spin-dependent local random potentials, is solved within dynamical mean-field theory. This allows us to present a comprehensive picture of the thermodynamic properties of this system. In particular, we show that for a fixed total number of fermions spin-dependent disorder induces a magnetic polarization. The magnetic response of the polarized system differs from that of a system with conventional disorder.

Ulrich Schneider, Lucia Hackerm uller, Thorsten Best +3 more

Laurent Sanchez-Palencia, V. Ahufinger, Adrian Kantian +3 more

We investigate theoretically the low-temperature physics of a two-component ultracold mixture of bosons and fermions in disordered optical lattices. We focus on the strongly correlated regime. We show that, under specific conditions, composite fermions, made of one fermion plus one bosonic hole, form. The composite picture is used to derive an effective Hamiltonian whose parameters can be controlled via the boson-boson and the boson-fermion interactions, the tunneling terms and the inhomogeneities. We finally investigate the quantum phase diagram of the composite fermions and we show that it corresponds to the formation of Fermi glasses, spin glasses, and quantum percolation regimes.

Brian DeMarco

Bo-Nan Jiang, Jun Qian, Wenli Wang +2 more