Se p 19 99 The magnetism of the t − t ′ Hubbard model

The magnetism of the t − t ′ Hubbard model Abstract The magnetic properties of the t − t ′ Hubbard model in the two dimensional square lattice are studied within an unrestricted Hartree Fock approximation in real space. The interplay between antiferromagnetism, ferromagnetism, phase separation and in-homogeneous magnetic textures is studied. It is shown that, at sufficiently large values of t ′ /t, a rich fenomenology is to be expected between the antiferromagnetic phase at half filling and the ferromagnetic phase at lower fillings.