Anderson localization induced by complex potential. (24th September 2021)

• Record Type: Journal Article
• Authors: Wang, R; Zhang, K L; Song, Z
• Is Part Of: Journal of physics communications. Volume 5:Number 9(2021)
• Publication Date: 2021-09-24
• Subjects: Anderson localization -- non-Hermitian -- Su-Schrieffer-Heeger model -- Aubry-Andre-Harper model -- quasiperiodic potential; Physics -- Periodicals; 530.05
• DOI: 10.1088/2399-6528/ac261f
• Languages: English
• ISSNs: 2399-6528

Abstract

Abstract: In the Hermitian regime, uncorrelated disorder potential in one-dimensional lattice induces Anderson localization, whereas quasiperiodic potential can lead to both localized and extended phases, depending on the potential strength. In this study, we investigate the non-Hermitian regime. We analytically and numerically study Anderson localization in a one-dimensional lattice with the non-Hermitian complex disorder and quasiperiodic potential. We present a non-Hermitian Su-Schrieffer-Heeger (SSH) chain and demonstrate that the Hermitian counterpart with full real spectrum is a standard Anderson chain, which indicates that a nonzero imaginary disorder on-site potential can induce standard Anderson localization. We further demonstrate that the non-Hermitian Aubry-André -Harper (AAH) model exhibits a transition in parameter space, which separates the localization and delocalization phases and is determined by the self-duality of the model. This indicates that a pure imaginary quasiperiodic potential plays the same role as a real quasiperiodic potential in the transition point between localization and delocalization. Notably, a system with complex quasiperiodic potential exhibits an interference-like pattern on the transition points, which arises from the interplay between the real and imaginary components.