Spontaneous breaking of charge symmetry in a frustrated one-dimensional Hubbard Model: Dimer states from charge motion

We give numerical evidence that a single hole in an otherwise half-filled U = infinity Hubbard model can favour one of the two natural sublattices. We study the Linear chain with competing nearest-neighbour and next-nearest-neighbour hopping, which frustrates the usual Nagaoka ferromagnetism. The spin and charge degrees of freedom separate but are not independent. Combined with the hole residing dominantly on one sublattice, we find a corresponding dimerisation of the underlying spin wavefunction which enhances motion of the hole predominantly along its chosen sublattice.