Delocalization of two interacting particles in the two-dimensional Harper model

Abstract

We study the problem of two interacting particles in a two-dimensional quasiperiodic potential of the Harper model. We consider an amplitude of the quasiperiodic potential such that in absence of interactions all eigenstates are exponentially localized while the two interacting particles are delocalized showing anomalous subdiffusive spreading over the lattice with the spreading exponent $b\approx 0.5$ instead of a usual diffusion with $b=1$. This spreading is stronger than in the case of a correlated disorder potential with a one particle localization length as for the quasiperiodic potential. At the same time we do not find signatures of ballistic FIKS pairs existing for two interacting particles in the one-dimensional Harper model.

10 pages, 10 figures, high resolution figures available at: http://www.quantware.ups-tlse.fr/QWLIB/tipharper2d

References in corpus (5)

• Observation of many-body localization of interacting fermions in a quasi-random optical lattice
• Destruction of Anderson localization by a weak nonlinearity
• Delocalization induced by nonlinearity in systems with disorder
• Nonlinear lattice waves in heterogeneous media
• Freed by interaction kinetic states in the Harper model

Cited by in corpus (4)

• Quantum jumps on Anderson attractors
• Electron pairing by Coulomb repulsion in narrow band structures
• Coulomb electron pairing in a tight-binding model of La-based cuprate superconductors
• Chaotic delocalization of two interacting particles in the classical Harper model