Magnetic solitons in a spin-1 Bose-Einstein condensate

TL;DR

This paper reports the discovery of a new type of magnetic soliton in a spin-1 Bose-Einstein condensate, revealing complex spin-dependent nonlinear phenomena beyond previous binary systems, with implications for quantum information and many-body physics.

Contribution

It introduces a novel magnetic soliton in a full spin-1 BEC system, expanding the understanding of vector solitons in quantum many-body systems beyond the Manakov limit.

Findings

Observation of magnetic solitons only in antiferromagnetic interactions

Use of magnetic shadowing technique for soliton detection

Potential for studying soliton interactions and quantum correlated states

Abstract

Vector solitons are a type of solitary, or non-spreading wavepacket occurring in a nonlinear medium comprised of multiple components. As such, a variety of synthetic systems can be constructed to explore their properties, from nonlinear optics to ultracold atoms, and even in human-scale metamaterials. In quantum systems such as photons or Bose-Einstein condensates (BECs), such vector nonlinearities offer a window into complex many-body dynamics, and offer possibilities for quantum communication and information processing. BECs have a rich panoply of internal hyperfine levels, or spin components, which make them a unique platform for exploring these solitary waves. However, existing experimental work has focused largely on binary systems confined to the Manakov limit of the nonlinear equations governing the soliton behavior, where quantum magnetism plays no role. Here we observe, using a ``magnetic shadowing'' technique, a new type of soliton in a spinor BEC, one that exists only when the underlying interactions are antiferromagnetic, and which is deeply embedded within a full spin-1 quantum system. Our approach opens up a vista for future studies of ``solitonic matter'' whereby multiple solitons interact with one another at deterministic locations, and eventually to the realization of quantum correlated states of solitons, a longstanding and unrealized goal.