Fermionic atoms trapped in a one-dimensional optical superlattice with harmonic confinement

Abstract

We study the ground-state properties of spin-1/2 fermionic atoms confined in a one-dimensional optical superlattice with harmonic confinement by using the density-matrix renormalization group method. For this purpose, we consider an ionic Hubbard model that has superlattice potentials with two-site periodicity. We find that several different types of insulating regimes coexist even if the number of atoms at each site is not an integer, but its average within the unit cell is an integer or half integer. This is contrasted to the coexisting phase of the metallic and Mott-insulating regimes known for the ordinary Hubbard model in an optical lattice. The phase characteristics are elucidated by investigating the profiles of the atom density, the local density ͑spin͒ fluctuations, the double occupation probability, and the spin correlations in detail.

Topological Mott insulators of ultracold atomic mixtures induced by interactions in one-dimensional optical superlattices

“…Cold atomic systems in 1D quasiperiodic lattices have been extensively studied [19][20][21][22] with a focus on the Anderson localization 17 . However, their nontrivial topological features are recognized only very recently 23,24 .…”

The asymmetric Hubbard model with a confining potential: The partial filling case

“…Indistinguishable fermions trapped in an optical potential have been studied using Monte Carlo methods and density matrix renormalization group [8][9][10][11]. In these works, the fermions were modelled by the Hubbard model, and they consider a quadratic potential which describes the trap.…”

Analysis of Particle Transfer by Periodic Lattice Modulation for Ultracold Fermionic Atom Systems in Three-Dimensional Optical Lattice

“…The systems, both bosonic and fermionic, are well described by the Hubbard model, whose numerical analysis are performed in various methods, i.e., Gutzwiller variational approach (GVA), [1][2][3] dynamical mean-field theory (DMFT), [4][5][6] density matrix renormalization group (DMRG) method, [7][8][9][10] quantum Monte Carlo (QMC) method [11][12][13] and so on.…”