DMRG studies for 1-D random Hubbard chain close to the half-filling Original Research Article

We numerically study the repulsive Hubbard model with random potential by using the density-matrix renormalization group method. When a few holes are doped to the half-filling, i.e., in slightly doped Mott insulator, we clearly find that “Mott plateaus” and “hole localized valleys” well-separately form in strong on-site repulsive U/tU/t and strong randomness. These nano-scale structures are non-trivial ones created due to strong correlation incorporating randomness. We suggest that these structures qualitatively capture phenomena seen in heavily under-doped high-TcTc superconductors, while cold atomic Fermi gases loaded on an optical lattice can experimentally confirm the structures under a well-controllable manner.