2007/02/26 by Jize Zhao, Kazuo Ueda, Xiaoqun Wang · 2 citations
Materials Science · Physics and Astronomy · #Charge (physics) #Charge density wave #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Density matrix renormalization group #Ground state #Hubbard model #Lattice (music) #Organic and Molecular Conductors Research #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quasiparticle #Renormalization group #Superconductivity #cond-mat.str-el
paper · pdf · doi:10.1143/jpsj.76.114711
published as JPSJ 76, 114711(2007) · 7 pages, 7 figures
arxiv created 2007/02/26 · openalex publication_date 2007/11/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study a one-dimensional SU(N) Hubbard model with an attractive on-site interaction and N>2 at half-filling on the bipartite lattice using density-matrix renormalization-group method and a perturbation theory. We find that the ground state of the SU(N) Hubbard model is a charge density wave state with two-fold degeneracy. All the excitations are found to be gapful, resulting in an insulating ground state, on contrary to that in the SU(2) case. Moreover, the charge gap is equal to the Cooperon gap, which behaves as -2Nt2/(N-1)U in the strong coupling regime. However, the spin gap Δs and the quasiparticle gap Δ1 as well open exponentially in the weak coupling region, while in the strong coupling region, they linearly depend on U such that Δs∼ -U(N-1) and Δ1∼ -U(N-1)/2.