arXiv:cond-mat/0511557 · Journal of Physics A Mathematical and General
Influence of anisotropic next-nearest-neighbour hopping on diagonal charge-striped phases
Volodymyr Derzhko
Abstract
We consider the model of a strongly correlated system of electrons on a two-dimensional square lattice described by an extended Falicov–Kimball Hamiltonian where the stability of some axial and diagonal striped phases was proved. Introducing a next-nearest-neighbour hopping, small enough not to destroy the striped structure, we examine rigorously how the presence of the next-nearest-neighbour hopping anisotropy reduces the π/2-rotation degeneracy of the diagonal-striped phase. The effect appears to be similar to that in the case of anisotropy of the nearest-neighbour hopping: diagonal stripes are oriented in the direction of the weaker next-nearest-neighbour hopping.