I am working on the droplet state in a Bose-Bose mixture. I have a question about the difference between the droplet liquid state and the soliton state: How we can treat a droplet state? And how do we know that we have a droplet state?
Bright/dark solitons are solutions to the GPE. Hence, they are predicted from mean-field theory and stabilised by mechanisms within this approximation.
Quantum liquid droplets are stabilised by beyond mean-field theory corrections, Lee-Huang-Yang (LHY) terms. The phyisical mechanism in their production, and hence in their dynamics and stability, is different.
Quantum droplest and brigth solitons are two different states in BEC. Indeed the droplets are three-dimensional solutions that exist even in free space in contrast, solitons require the gas to remain effectively one dimensional.