Abstract
Employing time-dependent density-functional theory, we have studied dynamical equilibration and binary head-on collisions of quantum droplets taking as a case of study droplets made of a $^{39}\mathrm{K}\text{\ensuremath{-}}^{39}\mathrm{K}$ Bose mixture. The phase space of collision outcomes is extensively explored by performing fully three-dimensional calculations with effective single-component Quantum Monte Carlo-based and two-component LHY-corrected mean-field functionals. We exhaustively explored the important effect---not considered in previous studies---of the initial population ratio deviating from the optimal mean-field value ${N}_{2}/{N}_{1}=\sqrt{{a}_{11}/{a}_{22}}$. Both stationary and dynamical calculations indicate sensitivity to an initial nonoptimal concentration. When three-body losses (3BL) are present our two-component approach allows to theoretically address situations in which they mainly act on one of the components of the mixture. Our approach also allows to simultaneously explore the effect on the simulation of population imbalance and 3BL, which are coupled when they act.
Highlights
The collision of liquid drops is one of the more fundamental and complex problems addressed in fluid dynamics, with implications in basic research and applications, e.g., in microfluidics, formation of rain drops, ink-jet printing, or spraying for combustion, painting, and coating [1,2,3,4]
Employing time-dependent density-functional theory, we have studied dynamical equilibration and binary head-on collisions of quantum droplets taking as a case of study droplets made of a 39K - 39K Bose mixture
The recent study of head-on 39K - 39K droplet collisions [38] offers a new avenue of research by extending the study of quantum droplet collisions—previously restricted to the case of helium droplets [32] to much lower density and temperature ranges of ultradilute cold Bose gas mixtures. We have taken this experiment as a case of study to theoretically analyze the influence of some elements not considered in the simulations carried out in that work
Summary
The collision of liquid drops is one of the more fundamental and complex problems addressed in fluid dynamics, with implications in basic research and applications, e.g., in microfluidics, formation of rain drops, ink-jet printing, or spraying for combustion, painting, and coating [1,2,3,4]. In this work we present one such framework for the description of binary collisions of ultradilute quantum droplets It uses a QMC-based functional which takes into account the effective range of the interactions and a two-component MF+LHY functional which enables the study of nonequilibrated drops and a more realistic consideration of 3BL. The above framework is the most general version of a twocomponent equal-masses Bose-Bose energy functional, and it allows for all possible ρ1 and ρ2 values This functional can be reduced to an effective one-component functional, which is the one mostly used in the study of Bose-Bose mixtures, if one uses the result that the stability of a dilute Bose-Bose mixture li√es in a very narrow range of optimal partial densities ρ1/ρ2 = a22/a11 [40,41]. The QMC functional correctly incorporates the two relevant scattering parameters of this mixture, i.e., the s-wave scattering lengths and the effective ranges
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
