Ground-state properties of the one-dimensional attractive Hubbard model with confinement; A Comparative study

Hu, J.-H.*; Wang, J.-J.*; Xianlong, G.*; Okumura, Masahiko*   ; Igarashi, Ryo; Yamada, Susumu  ; Machida, Masahiko  

We revisit the one-dimensional attractive Hubbard model by using the Bethe-ansatz-based density-functional theory and density-matrix renormalization method. The ground-state properties of this model are discussed in details for different fillings and different confining conditions in weak-to-intermediate coupling regime. We investigate the ground-state energy, energy gap, and pair-binding energy and compare them with those calculated from the canonical Bardeen-Cooper-Schrieffer approximation. We find that the Bethe-ansatz-based density-functional theory is computationally easy and yields an accurate description of the ground-state properties for weak-to-intermediate interaction strength, different fillings, and confinements.