Numerical simulations of strongly correlated fermions confined in 1D optical lattices

On the basis of quantum Monte Carlo (QMC) simulations we study the formation of Mott domains in the one-dimensional Hubbard model with an additional confining potential. We find evidences of quantum critical behavior at the boundaries of the Mott-insulating regions. A local compressibility defined to characterize the local phases exhibits a non-trivial critical exponent on entering the Mott-insulating domains. Both the local compressibility and the variance of the local density show universality with respect to the confining potential. We also study the momentum distribution function of the trapped system, and determine its phase diagram.