Seminarium KMMF "Teoria Dwoistości"

One of the long-standing and only partially solved problems oftheoretical condensed matter physics and mathematical physics is todemonstrate that ground states of some of the versions of the Hubbardmodel can exhibit a ferromagnetic ordering. In my talk I will present aresult showing that crucial for this is the character of the lattice onwhich the Hubbard model is formulated: while on simple cubic lattices noferromagnetic ordering seems to be possible, it can naturally arise, forlow densities of magnetic moment carriers, on so-called frustratedlattices.