Density-matrix renormalization study of frustrated fermions on a triangular lattice

We show that the two-dimensional density-matrix renormalization analysis is useful to detect the symmetry breaking in the fermionic model on a triangular lattice. Under the cylindrical boundary conditions with chemical potentials on edge sites, we find that the partially open edges work as perturbations which makes the spacial structure of a bulk long-range order but not the short-range ones appear directly in the local physical quantities. We also demonstrate that the ordinary size scaling analysis on the charge gap as well as that of the local charge density under this boundary condition could determine the metal-insulator phase boundary, which scales almost perfectly with the density of states and the exact solutions in the weak- and strong-coupling regions, respectively.