Nonlocal quantum superpositions of bright matter-wave solitons and dimers

TL;DR

This paper explores the creation and analysis of nonlocal quantum superpositions of bright matter-wave solitons and dimers through scattering at barriers, with potential applications in quantum interferometry.

Contribution

It provides analytical and numerical analysis of quantum superpositions in bright solitons and dimers, highlighting their observable signatures in interferometric setups.

Findings

Quantum superpositions can be generated via scattering at barriers.

Interference patterns are observable in the centre-of-mass density.

Results are applicable to systems with around 100 particles.

Abstract

The scattering of bright quantum solitons at barrier potentials in one-dimensional geometries is investigated. Such protocols have been predicted to lead to the creation of nonlocal quantum superpositions. The centre-of-mass motion of these bright matter-wave solitons generated from attractive Bose-Einstein condensates can be analysed with the effective potential approach. An application to the case of two particles being scattered at a delta potential allows analytical calculations not possible for higher particle numbers as well as a comparison with numerical results. Both for the dimer and a soliton with particle numbers on the order of N = 100, we investigate the signatures of the coherent superposition states in an interferometric setup and argue that experimentally an interference pattern would be particularly well observable in the centre-of-mass density. Quantum superposition states of ultra-cold atoms are interesting as input states for matter-wave interferometry as they could improve signal-to-noise ratios.