%0 Journal Article
%T Hidden string order in a hole-superconductor with extended correlated hopping
%A Ravindra W. Chhajlany
%A Przemys£¿aw R. Grzybowski
%A Julia Stasi¨½ska
%A Maciej Lewenstein
%A Omjyoti Dutta
%J Physics
%D 2015
%I arXiv
%X Ultracold fermions in a one-dimensional, spin-dependent, optical lattice are described by a non-standard Hubbard model with next-nearest-neighbour correlated hopping. Periodic driving of the lattice allows wide tuning of the system parameters. We solve this model exactly for a special value of the correlated hopping. The solution reveals the general properties of this system for arbitrary filling: exact and asymmetric spin-charge separation, a gapless spectrum of lowest energy excitations, a spin-gap, which may be interpreted in terms of collective hole pairing and a non-vanishing den Nijs-Rommelse type string correlator. Numerical studies away from the integrable point show the persistence of both long range string order and spin-gap.
%U http://arxiv.org/abs/1508.00404v1