Variational Description of Mott Insulators

The Gutzwiller wave function for a strongly correlated model can, if supplemented with a long-range Jastrow factor, provide a proper variational description of Mott insulators, so far unavailable. We demonstrate this concept in the prototypical one-dimensional $t-t^{\prime }$ Hubbard model, where at half-filling we reproduce all known phases, namely, the ordinary Mott undimerized insulator with power-law spin correlations at small $t^{\prime }/t$, the spin-gapped metal above a critical $t^{\prime }/t$ and small $U$, and the dimerized Mott insulator at large repulsion.