Aspects of the ground state of the $U=\infty$ Hubbard ladder

Abstract

We consider two aspects of the ground state of the $U=\infty$ Hubbard ladder: ferromagnetism and the metal-insulator transition at quarter-filling. First, we present rigorous results for the $U=\infty$ Hubbard ladder in the limit of the large inter-chain hopping ($t_{\perp }/t\to \infty$). In this limit, the total spin $S$ of the ground state is shown to be zero for the electron density $n\le 0.5$ and its maximum ($S=S_{max}$) for $n>0.5$. The charge gap at quarter-filling is $2t_{\perp }$. We extend these results to finite $t_{\perp }/t$ by means of the density-matrix renormalization group method. We estimate the phase boundaries with respect to spontaneous magnetization and the charge gap at quarter-filling for finite $t_{\perp }/t$. Applying the extended Aharonov-Bohm method, we give numerical evidence that the critical ratio $t_{\perp }/t$, above which the charge gap opens, is less than 0.001. Ferromagnetism in the t-J ladder is briefly discussed.

24 pages, RevTex, 11 figures, to appear in Phys.Rev.B

References in corpus (13)

• Weak Coupling Phase Diagram of the Two Chain Hubbard Model
• Correlations in a two--chain Hubbard model
• Pairing and Excitation Spectrum in doped t-J Ladders
• Evidence for a superfluid density in t--J ladders
• Spin Gap Fixed Points in the Double Chain Problem
• Luttinger liquid behaviour and superconducting correlations in t-J ladders
• Ground State Properties of the Two-Dimensional t-J Model
• Insulator-Metal Transition in the One and Two-Dimensional Hubbard Models
• Quantum Monte Carlo study of the pairing correlation in the Hubbard ladder
• Ferromagnetism in the Infinite-U Hubbard Model
• A possible phase diagram of a t-J ladder model
• Detection of pairing from the extended Aharonov-Bohm period in strongly correlated electron systems
• Extended Aharonov-Bohm period analysis of strongly correlated electron systems

Cited by in corpus (14)

• Phases of the infinite U Hubbard model
• Doped AB_2 Hubbard Chain: Spiral, Nagaoka and RVB States, Phase Separation and Luttinger Liquid Behavior
• Magnetic properties of the Hubbard model on three-dimensional lattices: fluctuation-exchange and two-particle self-consistent studies
• States induced in the single-particle spectrum by doping a Mott insulator
• Phase-separated Ferromagnetism in Spin-imbalanced Fermi Atoms Loaded on an Optical Ladder: a DMRG study
• The spectral function of Mott-insulating Hubbard ladders: From fractionalized excitations to coherent quasi-particles
• Existence of Saturated Ferromagnetic and Spiral States in 1D Lieb-Ferrimagnetic Models away from Half-Filling
• Relationship between single-particle excitation and spin excitation at the Mott Transition
• Nagaoka's theorem in the Holstein-Hubbard model
• Single-particle spectral function of quarter-filled ladder systems
• Emergence and spectral-weight transfer of electronic states in the Hubbard ladder
• Doping control of realization of an extended Nagaoka ferromagnetic state from the Mott state
• Stability of ferromagnetism in many-electron systems
• Electronic modes induced by spin and charge perturbations in Mott and Kondo insulators