Compressibility enhancement in an almost staggered interacting Harper model

Abstract

We discuss the compressibility in the almost staggered fermionic Harper model with repulsive interactions in the vicinity of half-filling. It has been shown by Kraus et al. [33] that for spinless electrons and nearest neighbors electron-electron interactions the compressibility in the central band is enhanced by repulsive interactions. Here we would like to investigate the sensitivity of this conclusion to the spin degree of freedom and longer range interactions. We use the Hartree-Fock (HF) approximation, as well as density matrix renormalization group (DMRG) calculation to evaluate the compressibility. In the almost staggered Harper model, the central energy band is essentially flat and separated from the other bands by a large gap and therefore, the HF approximation is rather accurate.In both cases the compressibility of the system is enhanced compare to the non-interacting case, although the enhancement is weaker due to the inclusion of Hubbard and longer ranged interactions.

arXiv commentVersion published in PRB

References in corpus (27)

• The density-matrix renormalization group
• Anderson localization of a non-interacting Bose-Einstein condensate
• Realization of the Hofstadter Hamiltonian with ultracold atoms in optical lattices
• Topological States and Adiabatic Pumping in Quasicrystals
• Realizing the Harper Hamiltonian with Laser-Assisted Tunneling in Optical Lattices
• The Statistical Theory of Quantum Dots
• Experimental observation of the Anderson transition with atomic matter waves
• Direct observation of a localization transition in quasi-periodic photonic lattices
• Many-Body Localization in a Quasiperiodic System
• Observation of Topological Phase Transitions in Photonic Quasicrystals
• New Trends in Density Matrix Renormalization
• Topological Zero-Energy Modes in Gapless Commensurate Aubry-André-Harper Models
• Topological Equivalence between the Fibonacci Quasicrystal and the Harper Model
• Bipartite Fluctuations as a Probe of Many-Body Entanglement
• Anderson localization in Bose-Einstein condensates
• Topological edge states in the one-dimensional super-lattice Bose-Hubbard model
• Correlated Fermions in a one-dimensional quasiperiodic potential
• Topological equivalence of crystal and quasicrystal band structures
• Absence of bimodal peak spacing distribution in the Coulomb blockade regime
• Interacting fermions in self-similar potentials
• Fractional topological states of dipolar fermions in one-dimensional optical superlattices
• Insulator-Metal Transition in the One and Two-Dimensional Hubbard Models
• Interacting particles at a metal-insulator transition
• Chern and Majorana Modes of Quasiperiodic Systems
• Theory of charge sensing in quantum-dot structures
• Topological Mott insulators of ultracold atomic mixtures induced by interactions in one-dimensional optical superlattices
• Enhanced compressibility due to repulsive interaction in the Harper model

Cited by in corpus (3)

• Topological spin excitations in Harper-Heisenberg spin chains
• Quasiperiodic criticality and spin-triplet superconductivity in superconductor-antiferromagnet moire patterns
• Persistent current in an almost staggered Harper model