Multifractality of correlated two-particle bound states in quasiperiodic chains

Abstract

©2020 American Physical Society, We consider the quasiperiodic Aubry-Andre chain in the insulating regime with localized single-particle states. Adding local interaction leads to the emergence of extended correlated two-particle bound states. We analyze the nature of these states, including their multifractality properties. We use a projected Green function method to compute numerically participation numbers of eigenstates and analyze their dependence on the energy and the system size. We then perform a scaling analysis. We observe multifractality of correlated extended two-particle bound states, which we confirm independently through exact diagonalization