Repulsion driven metallic phase in the ground state of the half-filled $t-t^{\prime }$ ionic Hubbard chain

Abstract

An unusual metallic phase is proven to develop in the one dimensional ionic Hubbard model, at half-filling and zero magnetization, at intermediate electron-electron repulsion $U$ when second neighbors hopping is allowed and tuned close to a topological Lifshitz transition (connected with a change of the Fermi surface in the non-interacting system). The metallic state lies between a band insulator phase at low repulsion and a correlated (Mott-like) insulator phase at high repulsion. In approaching the later, the metal supports spontaneous bond charge dimerization and antiferromagnetic correlations. The ground state of the system, attainable by cold atoms in optical lattices for a wide range of the parameter $U$, is extensively explored by numerically exact density-matrix renormalization-group (DMRG) calculations. A combination of mean field and effective field theory (bosonization) provides an analytical understanding of the physical processes underlying the observed phase transitions.

18 pages, 16 figures, accepted in Phys.Rev. A

References in corpus (13)

• Orbital superfluidity in the $P$-band of a bipartite optical square lattice
• Quantisation and its breakdown in a Hubbard-Thouless pump
• Ground-state phase diagram of the one-dimensional half-filled extended Hubbard model
• Semi-synthetic zigzag optical lattice for ultracold bosons
• Splitting of topological charge pumping in an interacting two-component fermionic Rice-Mele Hubbard model
• Interaction-resistant metals in multicomponent Fermi systems
• Bose-Hubbard triangular ladder in an artificial gauge field
• Phase diagram of the one-dimensional Hubbard model with next-nearest-neighbor hopping
• Band-Insulator-Metal-Mott-Insulator transition in the half--filled $t-t^{\prime }$ ionic-Hubbard chain
• Topological Lifshitz Transitions, Orbital Currents, and Interactions in Low-dimensional Fermi Gases in Synthetic Gauge Fields
• Spectrum, Lifshitz transitions and orbital currents in frustrated fermionic ladders with a uniform flux
• Two-fluid coexistence and phase separation in a one dimensional model with pair hopping and density interactions
• Bosonization study of a generalized statistics model with four Fermi points

Cited by in corpus (1)

• Orbital antiferromagnetic currents in a frustrated fermionic ladder