Three-dimensional strong localization of matter waves by scattering from atoms in a lattice with a confinement-induced resonance

TL;DR

This paper explores how ultracold atoms in a 3D optical lattice can create a disordered potential that enables strong localization of matter waves, using Feshbach and confinement-induced resonances to tune interactions.

Contribution

It demonstrates the feasibility of achieving 3D strong localization of matter waves through controlled atomic interactions in a lattice-based disordered system.

Findings

Large number of localized states can be produced at low energy

Effective scattering length can be tuned via Feshbach and confinement resonances

Localization depends on the interaction strength and atomic arrangement

Abstract

The possibility of using ultracold atoms to observe strong localization of matter waves is now the subject of a great interest, as undesirable decoherence and interactions can be made negligible in these systems. It was proposed that a static disordered potential can be realized by trapping atoms of a given species in randomly chosen sites of a deep 3D optical lattice with no multiple occupation. We analyze in detail the prospects of this scheme for observing localized states in 3D for a matter wave of a different atomic species that interacts with the trapped particles and that is sufficiently far detuned from the optical lattice to be insensitive to it. We demonstrate that at low energy a large number of 3D strongly localized states can be produced for the matter wave, if the effective scattering length describing the interaction of the matter wave with a trapped atom is of the order of the mean distance between the trapped particles. Such high values of the effective scattering length can be obtained by using a Feshbach resonance to adjust the free space inter-species scattering length and by taking advantage of confinement-induced resonances induced by the trapping of the scatterers in the lattice.