  We study transport properties of the half-filled two-dimensional (2D) Hubbard
model with spatially varying interactions, where a pattern of interacting and
non-interacting sites is formed. We use Determinantal Quantum Monte Carlo
method to calculate the double occupation, effective hopping and Drude weight.
These data point to two phase transitions, driven by fermionic correlations.
The first is the expected metal to a Mott insulating state. The second one, is
an exotic transition from a Mott insulating state to a highly anisotropic
metal, that takes place at large values of the fermion-fermion interaction.
This second transition occurs when the layers formed by the spatially varying
interactions decouple due to the suppression of the hopping between interacting
and non-interacting sites, leading to fermionic transport along the
non-interacting ones.
