Enhanced compressibility due to repulsive interaction in the Harper model

Abstract

We study the interplay between repulsive interaction and an almost staggered on-site potential in one-dimension. Specifically, we address the Harper model for spinless fermions with nearest-neighbor repulsion, close to half-filling. Using density matrix renormalization group (DMRG), we find that, in contrast to standard behavior, the system becomes more compressible as the repulsive interaction is increased. By generating a low-energy effective model, we unveil the effect of interactions using mean-field analysis: the density of a narrow band around half-filling is anti-correlated with the on-site potential, whereas the density of lower occupied bands follows the potential and strengthens it. As a result, the states around half-filling are squeezed by the background density, their band becomes flatter, and the compressibility increases.

7 pages, 3 figures

References in corpus (7)

• Many-Body Physics with Ultracold Gases
• Realization of the Hofstadter Hamiltonian with ultracold atoms in optical lattices
• Realizing the Harper Hamiltonian with Laser-Assisted Tunneling in Optical Lattices
• Many-Body Localization in a Quasiperiodic System
• Observation of Topological Phase Transitions in Photonic Quasicrystals
• Anderson localization in Bose-Einstein condensates
• Large Negative Electronic Compressibility of LaAlO3-SrTiO3 Interfaces with Ultrathin LaAlO3 Layers

Cited by in corpus (12)

• The 6D quantum Hall effect and 3D topological pumps
• Topological spin excitations in Harper-Heisenberg spin chains
• Many-body localization in the interpolating Aubry-André-Fibonacci model
• Incommensurability enabled quasi-fractal order in 1D narrow-band moiré systems
• Second-order topological modes in two-dimensional continuous media
• Dense gaps and scaling relations in the interacting Aubry-Andre' model
• Short-range interactions are irrelevant at the quasiperiodic-driven Luttinger Liquid to Anderson Glass transition
• Quasiperiodic criticality and spin-triplet superconductivity in superconductor-antiferromagnet moire patterns
• Interaction-induced reentrance of Bose glass and quench dynamics of Bose gases in twisted bilayer and quasicrystal optical lattices
• Compressibility enhancement in an almost staggered interacting Harper model
• Persistent current in an almost staggered Harper model
• Effective Luttinger parameter and Kane-Fisher effect in quasiperiodic systems