Localization transition in weakly-interacting Bose superfluids in one-dimensional quasiperdiodic lattices

TL;DR

This paper investigates how collective excitations in weakly-interacting Bose superfluids in one-dimensional quasiperiodic lattices undergo a sharp localization transition, combining numerical and analytical methods to map the transition.

Contribution

It provides a numerical phase diagram and an analytical model linking the localization transition to an effective multiharmonic quasiperiodic system.

Findings

Sharp localization transition at intermediate interactions and quasiperiodic amplitudes

Extended low-energy and localized high-energy states coexist

Analytical mapping to an effective multiharmonic quasiperiodic system

Abstract

We study the localization of collective pair excitations in weakly-interacting Bose superfluids in one-dimensional quasiperiodic lattices. The localization diagram is first determined numerically. For intermediate interaction and quasiperiodic amplitude we find a sharp localization transition, with extended low-energy states and localized high-energy states. We then develop an analytical treatment, which allows us to quantitatively map the localization transition into that of an effective multiharmonic quasiperiodic system.