Observation of sine-Gordon-like solitons in a spinor Bose-Einstein condensate

TL;DR

This paper reports the experimental creation and control of sine-Gordon-like solitons in a spinor Bose-Einstein condensate, demonstrating elastic collisions and validating theoretical models.

Contribution

It introduces a reproducible phase-imprinting method to generate and manipulate sine-Gordon-like solitons in spinor BECs, enabling detailed study of their interactions.

Findings

Soliton velocity is tunable via quadratic Zeeman shift.

Observed elastic collisions match numerical simulations.

Phase shifts confirm pairwise soliton interactions.

Abstract

We experimentally generate sine-Gordon-like solitons in a spin-1 spinor Bose-Einstein condensate (BEC) utilizing a robust and reproducible local phase-imprinting scheme. We find that the soliton velocity can be tuned by the effective quadratic Zeeman shift. This enables the investigation of controlled soliton interactions, in which we observe the characteristic elastic collision behavior of the integrable sine-Gordon model. The spatial displacement -- the so-called phase shift -- between incoming and outgoing solitons, the signature of their pairwise interaction, is found to be in quantitative agreement with numerical spin-1 simulations within the error bars. These results establish spinor BECs as a highly controllable experimental platform for studying aspects of the dynamics of sine-Gordon-like models.