Observation of magnetic solitons in two-component Bose-Einstein condensates

TL;DR

This paper reports the experimental observation and characterization of magnetic solitons in a two-component Bose-Einstein condensate, revealing their non-dispersive dynamics and interactions during collisions.

Contribution

It introduces a novel interferometric technique to fully characterize magnetic solitons in ultracold gases and explores their collision dynamics.

Findings

Magnetic solitons exhibit long-lived, non-dispersive oscillatory motion.

Multiple solitons can be imprinted and manipulated to study binary collisions.

The trajectories of soliton collisions depend on their magnetization.

Abstract

We experimentally investigate the dynamics of spin solitary waves (magnetic solitons) in a harmonically trapped, binary superfluid mixture. We measure the in-situ density of each pseudospin component and their relative local phase via an interferometric technique we developed, and as such, fully characterise the magnetic solitons while they undergo oscillatory motion in the trap. Magnetic solitons exhibit non-dispersive, dissipationless long-time dynamics. By imprinting multiple magnetic solitons in our ultracold gas sample, we engineer binary collisions between solitons of either same or opposite magnetisation and map out their trajectories.