Statics and dynamics of atomic dark-bright solitons in the presence of delta-like impurities

Bound states of an ultracold atom interacting with a set of stationary impurities

In this manuscript we analyse properties of bound states of an atom interacting with a set of static impurities. We begin with the simplest system of a single atom interacting with two static impurities. We consider two types of atom-impurity interaction: (i) zero-range potential represented by regularized delta, (ii) more realistic polarization potential, representing long-range part of the atom-ion interaction. For the former we obtain analytical results for energies of bound states. For the latter we perform numerical calculations based on the application of finite element method. Then, we …

Spontaneous formation of bright solitons in self-localized impurities in Bose-Einstein condensate

We study the formation of bright solitons in the impurity component of Bose-Einstein condensate (BEC)-impurity mixture by using the time-dependent Hartree-Fock-Bogoliubov theory. While we assume the boson-boson and impurity-boson interactions to be effectively repulsive, their character can be changed spontaneously from repulsive to attractive in the presence of strong anomalous correlations. In such a regime the impurity component becomes a system of effectively attractive atoms leading automatically to the generation of bright solitons. We find that this soliton decays at higher temperatures…

Scattering of atomic dark-bright solitons from narrow impurities

In this work, we study the collision of an atomic dark-bright soliton, in a two-component Bose-Einstein condensate, with a Gaussian barrier or well. First, we present the results of an experiment, illustrating the classical particle phenomenology (transmission or reflection) in the case of an equal barrier or well in both components. Then, motivated by the experimental observations, we perform systematic simulations considering not only the case of equal heights, but also the considerably more complex setting, where the potential affects only one of the two components. We systematically classi…

玻色-爱因斯坦凝聚体中强相关杂质的量子孤子链

Quantum soliton-trains of strongly correlated impurities in Bose-Einstein condensates

数值研究表明，浸没在BEC中的强相关杂质在自钉扎态下会因BEC介导的吸引性自相互作用和不相容原理形成量子孤子链，其动力学类似于亮物质波孤子，且少数杂质碰撞性质由量子统计决定。

Correlated quantum dynamics of two quenched fermionic impurities immersed in a Bose-Einstein Condensate

We unravel the nonequilibrium dynamics of two fermionic impurities immersed in a one-dimensional bosonic gas following an interspecies interaction quench from weak to strong repulsions. Monitoring the temporal evolution of the single-particle density of each species we reveal the existence of four distinct dynamical regimes. For weak interspecies repulsions both species either perform a breathing motion or the impurity density splits into two parts which interact and disperse within the bosonic cloud. Turning to strong interactions we observe the formation of dark-bright states within the mean…

Scattering of a dark-bright soliton by an impurity

We study the dynamics of a dark-bright soliton interacting with a fixed impurity using a mean-field approach. The system is described by a vector nonlinear Schrodinger equation (NLSE) appropriate to multicomponent Bose-Einstein condensates. We use the variational approximation, based on hyperbolic functions, where we have the center of mass of the two components to describe the propagation of the dark and bright components independently. Therefore, it allows the dark-bright soliton to oscillate. The fixed local impurity is modeled by a delta function. Also, we use perturbation methods to deriv…