Constructing quantum dark solitons with stable scattering properties

A soliton is a class of solitary-wave solutions having specific mathematical properties, which universally appears in integrable systems. A quantum dark soliton is an emerging concept having theoretical and experimental relevance. Although recent studies have proposed quantum states with density profiles similar to those of classical dark solitons, the concept of quantum dark solitons is not yet fully established in that their collision dynamics have not been examined. Here, we first construct dark soliton states that possess stable scattering properties that are unique to solitons using the Lieb-Liniger model, establishing a direct link between quantum and classical dark soliton theories.