Gapped solitons and periodic excitations in strongly coupled BEC

TL;DR

This paper classifies two types of localized solitons in strongly coupled cigar-shaped Bose-Einstein condensates, analyzing their properties, stability, and potential for trapping atoms, with implications for controlling condensate phases.

Contribution

It introduces a novel classification of solitons in strongly coupled BECs, including background-dependent periodic trains and background-free localized solitons, with stability analysis and control methods.

Findings

Localized solitons without background have a lower bound on wave-number.

Periodic soliton trains require a background and have a W-type density profile.

The W-type soliton is stable and suitable for atom trapping.

Abstract

It is found that localized solitons in the strongly coupled cigar shaped Bose-Einstein condensate form two distinct classes. The one without a background is an asymptotically vanishing, localized soliton, having a wave-number, which has a lower bound in magnitude. Periodic soliton trains exist only in the presence of a background, where the localized soliton has a \textit{W}-type density profile. This soliton is well suited for trapping of neutral atoms and is found to be stable under Vakhitov-Kolokolov criterion, as well as numerical evolution. We identify an insulating phase of this system in the presence of an optical lattice. It is demonstrated that the ${\it W}$-type density profile can be precisely controlled through trap dynamics.