Anderson localization of pairs in bichromatic optical lattices

TL;DR

This paper explores how two interacting atoms form bound states in a 1D quasi-periodic optical lattice, revealing how localization depends on interaction strength and the nature of single-particle states, with implications for experiments.

Contribution

It provides a quantum phase diagram for Anderson localization of bound pairs in a 1D quasi-periodic lattice, highlighting the dependence on single-particle state properties.

Findings

Bound state formation depends on the nature of single-particle states.

The pair binding energy varies with interaction strength and state type.

The phase diagram delineates localized, extended, and fractal regimes.

Abstract

We investigate the formation of bound states made of two interacting atoms moving in a one dimensional (1D) quasi-periodic optical lattice. We derive the quantum phase diagram for Anderson localization of both attractively and repulsively bound pairs. We calculate the pair binding energy and show analytically that its behavior as a function of the interaction strength depends crucially on the nature -extended, multi-fractal, localized- of the single-particle atomic states. Experimental implications of our results are discussed.