Controlled creation and decay of singly-quantized vortices in a polar magnetic phase

Y Xiao,A A Blinova,D S Hall,J Ruostekoski,L S Weiss,M O Borgh

doi:10.1038/s42005-021-00554-y

Abstract

Quantized vortices appear in physical systems from superfluids and superconductors to liquid crystals and high energy physics. Unlike their scalar cousins, superfluids with complex internal structure can exhibit rich dynamics of decay and even fractional vorticity. Here, we experimentally and theoretically explore the creation and time evolution of vortex lines in the polar magnetic phase of a trapped spin-1 87Rb Bose–Einstein condensate. A process of phase-imprinting a nonsingular vortex, its decay into a pair of singular spinor vortices, and a rapid exchange of magnetic phases creates a pair of three-dimensional, singular singly-quantized vortex lines with core regions that are filled with atoms in the ferromagnetic phase. Atomic interactions guide the subsequent vortex dynamics, leading to core structures that suggest the decay of the singly-quantized vortices into half-quantum vortices.

Highlights

Quantized vortices appear in physical systems from superfluids and superconductors to liquid crystals and high energy physics
Vortices in superfluids with internal degrees of freedom, such as those existing within spinor Bose–Einstein condensates (BECs)[1,2] and superfluid liquid He-33,4, exhibit a much richer phenomenology than do simple line vortices in scalar superfluids
A singly-quantized vortex (SQV) with 2π phase winding is unstable against splitting into a pair of halfquantum vortices (HQVs), each with π phase winding

Summary

Introduction

Quantized vortices appear in physical systems from superfluids and superconductors to liquid crystals and high energy physics Unlike their scalar cousins, superfluids with complex internal structure can exhibit rich dynamics of decay and even fractional vorticity. A process of phaseimprinting a nonsingular vortex, its decay into a pair of singular spinor vortices, and a rapid exchange of magnetic phases creates a pair of three-dimensional, singular singly-quantized vortex lines with core regions that are filled with atoms in the ferromagnetic phase. We describe the controlled creation and subsequent time evolution of a pair of three-dimensional (3D) singular SQVs in the polar phase of a spin-1 87Rb BEC with ferromagnetic interatomic interactions. We numerically model the experimental conditions of vortex preparation and show how the ferromagnetic interactions influence and complicate the decay process as compared with polar interactions

Methods

Results

Conclusion