# Observation of a Spinning Top in a Bose-Einstein Condensate

## TL;DR

This paper demonstrates that vortices in elongated Bose-Einstein condensates behave like spinning tops, with experimental and theoretical evidence showing their precession and localized angular momentum, advancing understanding of vortex dynamics.

## Contribution

It introduces a theoretical model and experimental verification of vortex precession as spinning-top behavior in elongated BECs, highlighting localized angular momentum effects.

## Key findings

- Vortices precess like classical spinning tops.
- Angular momentum is confined near vortex cores.
- Real-time imaging captures vortex dynamics effectively.

## Abstract

Boundaries strongly affect the behavior of quantized vortices in Bose-Einstein condensates, a phenomenon particularly evident in elongated cigar-shaped traps where vortices tend to orient along a short direction to minimize energy. Remarkably, contributions to the angular momentum of these vortices are tightly confined to the region surrounding the core, in stark contrast to untrapped condensates where all atoms contribute $\hbar$. We develop a theoretical model and use this, in combination with numerical simulations, to show that such localized vortices precess in an analogous manner to that of a classical spinning top. We experimentally verify this spinning-top behavior with our real-time imaging technique that allows for the tracking of position and orientation of vortices as they dynamically evolve. Finally, we perform an in-depth numerical investigation of our real-time expansion and imaging method, with the aim of guiding future experimental implementation, as well as outlining directions for its improvement.