# Many-Body Quantum Dynamics in the Decay of Bent Dark Solitons of Bose-Einstein Condensates

## TL;DR

This paper investigates the complex quantum dynamics of bent dark solitons in two-dimensional Bose-Einstein condensates beyond mean-field theory, revealing vortex nucleation, core filling, and higher orbital excitations with potential experimental detection methods.

## Contribution

It introduces a correlated approach to study bent dark solitons, uncovering phenomena like vortex core filling and multi-orbital excitations not captured by mean-field models.

## Key findings

- Observation of vortex core filling due to quantum fluctuations
- Detection of higher-lying orbital excitations in density and coherence
- Identification of multi-orbital vortex-antidark structures

## Abstract

The beyond mean-field dynamics of a bent dark soliton embedded in a two-dimensional repulsively interacting Bose-Einstein condensate is explored. We examine the case of a single bent dark soliton comparing the mean-field dynamics to a correlated approach, the Multi-Configuration Time-Dependent Hartree method for Bosons. Dynamical snaking of this bent structure is observed, signaling the onset of fragmentation which becomes significant during the vortex nucleation. In contrast to the mean-field approximation "filling" of the vortex core is observed, leading in turn to the formation of filled-core vortices, instead of the mean-field vortex-antivortex pairs. The resulting smearing effect in the density is a rather generic feature, occurring when solitonic structures are exposed to quantum fluctuations. Here, we show that this filling owes its existence to the dynamical building of an antidark structure developed in the next-to-leading order orbital. We further demonstrate that the aforementioned beyond mean-field dynamics can be experimentally detected using the variance of single shot measurements. Additionally, a variety of excitations including vortices, oblique dark solitons, and open ring dark soliton-like structures building upon higher-lying orbitals is observed. We demonstrate that signatures of the higher-lying orbital excitations emerge in the total density, and can be clearly captured by inspecting the one-body coherence. In the latter context, the localization of one-body correlations exposes the existence of the multi-orbital vortex-antidark structure.