Stability and dynamics of dark-bright solitons in spin-orbit- and Rabi-coupled binary Bose-Einstein condensates
Bharathidasan University（巴拉迪达桑大学）；Southern University of Science and Technology（南方科技大学）；Government College for Women (Autonomous), Kumbakonam（甘布康纳姆女子自治学院）；Indian Institute of Technology Guwahati（印度理工学院古瓦哈提分校）
K. Rajaswathi, R. Ravisankar, R. Radha, P. K. Mishra, P. Muruganandam
We investigate the stability and nonlinear dynamics of dark--bright solitons in a one-dimensional binary Bose--Einstein condensate subjected to synthetic spin--orbit and Rabi couplings. In the absence of spin--orbit coupling, we map the coupled Gross--Pitaevskii equations onto the integrable Manakov model to obtain exact dark--bright soliton solutions, providing a rigorous theoretical benchmark. We demonstrate that finite spin--orbit coupling breaks integrability by inducing spin-dependent phase gradients that drive component-wise spatial separation and intrinsic density oscillations. By contrast, coherent Rabi driving enforces phase locking between spin components and supports robust breather-like excitations. Furthermore, we derive analytical continuity relations for mass and spin current densities, mapping the internal spin dynamics onto an internal Josephson-junction framework in which the gauge field acts as a continuous spatial momentum bias. Using imaginary-time propagation together with Bogoliubov--de Gennes analysis, we systematically characterise ground-state phases and excitation spectra for both symmetric and asymmetric interaction regimes in homogeneous and harmonically trapped systems. Real-time simulations further demonstrate that synthetic gauge fields and interaction quenches drive the system far from equilibrium, triggering modulational-instability-induced multi-soliton fragmentation, breathing stripe patterns, and non-equilibrium transport. Our results highlight the interplay of synthetic gauge fields, external confinement, and interaction engineering as powerful tools for controlling the stability and internal dynamics of multicomponent quantum fluids.
In this paper we study the scattering of solitons in a binary Bose-Einstein Condensate (BEC) including SO- and Rabi-couplings. To this end, we derive a reduced ODE model in view to provide a variational description of the collisional dynamics. Also, we assume negative intra- and inter-component interaction strengths, such that one obtains localized solutions even in absence of external potentials. By performing extensive numerical simulations of this model we observe that, for specific conditions, the final propagation velocity of the scattered solitons could be highly sensitive to small chang…
We study the formation of stable bright solitons in quasi-one-dimensional (quasi-1D) spin-orbit- (SO-) and Rabi-coupled two pseudospinor dipolar Bose-Einstein condensates (BECs) of 164 Dy atoms in the presence of repulsive contact interactions. As a result of the combined attraction-repulsion effect of both interactions and the addition of SO and Rabi couplings, two kinds of ground states in the form of self-trapped bright solitons can be formed, a plane-wave soliton (PWS) and a stripe soliton (SS). These quasi-1D solitons cannot exist in a condensate with purely repulsive contact interactions…
We study the motion of a self-attractive Bose-Einstein condensate with pseudo-spin 1/2 driven by a synthetic Rabi (Zeeman-like) field. This field triggers the pseudo-spin dynamics resulting in a density redistribution between its components and, as a consequence, in changes of the overall density distribution. In the presence of an additional external potential, the latter produces a net force acting on the condensate and activates its displacement. As an example, here we consider the case of a one-dimensional condensate in a random potential.
We present the numerical results of the structure and dynamics of the self-bound ground state arising solely because of the presence of beyond mean field quantum fluctuation in spin-orbit coupled binary Bose-Einstein condensates in one dimension. Depending upon spin-obit (SO) and Rabi couplings, we observe that the ground state exhibits either quantum-bright (plane) or quantum-stripe soliton nature. We find an analytical soliton solution for non-zero SO coupling that matches quite well with the numerical results. Further, we investigate the dynamical stability of these solitons by adopting thr…
我们证明了由于偶极排斥接触相互作用而在中心平面上形成的强、稳定、可移动的准一维暗中亮偶极玻色-爱因斯坦凝聚体（BEC）孤子.在中等速度下，两个这样的孤子碰撞的头被发现是几乎没有变形的准弹性。本文还讨论了在实验室中利用相位印记产生偶极明中暗孤子的方案。在偶极二元BEC中可以形成丰富多样的暗中亮孤子，可以是一个暗中亮孤子与一个亮孤子耦合，也可以是两个暗中亮孤子耦合。结果表明，使用数值模拟在三个空间维度采用现实的相互作用参数的偶极164 Dy BEC和二进制164 Dy-162 Dy BEC。
We demonstrate stable and metastable vortex-bright solitons in a three-dimensional spin-orbit-coupled three-component hyperfine spin-1 Bose-Einstein condensate (BEC) using numerical solution and variational approximation of a mean-field model. The spin-orbit coupling provides attraction to form vortex-bright solitons in both attractive and repulsive spinor BECs. The ground state of these vortex-bright solitons is axially symmetric for weak polar interaction. For a sufficiently strong ferromagnetic interaction, we observe the emergence of a fully asymmetric vortex-bright soliton as the ground s…
We show how access to sufficiently flexible trapping potentials could be exploited in the generation of three-dimensional atomic bright matter-wave solitons. Our proposal provides a route towards producing bright solitonic states with good fidelity, in contrast to, for example, a non-adiabatic sweeping of an applied magnetic field through a Feshbach resonance.
A vortex-bright soliton can precess around a fix point. Here, we find numerically that the fixed point and the associated precessional orbits can be shifted by applying a constant driving force on the bright component, the displacement is proportional to the force with a minus sign. This robust dynamics is then discussed theoretically by treating the vortex-bright soliton as an effective point particle, explaining the observed dynamics and predicting new ones that are subsequently confirmed. By appropriately tuning the force, the vortex-bright soliton can be guided following an arbitrary traje…
Stable and mobile two-dimensional dipolar ring-dark-in-bright Bose-Einstein condensate soliton
我们证明了一个强大的，稳定的，移动的二维（2D）偶极环暗中亮（RDB）玻色-爱因斯坦凝聚体（BEC）孤子的排斥接触相互作用，受到谐波陷阱沿$y$方向垂直于偏振方向$z$。这样的RDB孤子有一个环形缺口（密度为零）印在一个2D亮孤子自由移动在$x-z$平面。在中等速度下，两个这样的孤子的迎头碰撞被发现是准弹性的，几乎没有变形。论证了利用相位印记产生RDB孤子的可能性。结果表明，使用数值模拟采用现实的相互作用参数在偶极$^{164}$ Dy BEC。
Two-dimensional bright and dark-in-bright dipolar Bose-Einstein condensate solitons on a one-dimensional optical lattice
研究了一维光格势场中各向异性、稳定、亮偶极和亮中暗偶极准二维玻色-爱因斯坦凝聚体（BEC）孤子的静态和动力学性质.这些孤子在垂直于一维OL陷阱的平面内运动，可以同时具有排斥和吸引的接触相互作用。明中暗孤子是亮孤子的激发态。孤子，当受到一个小的扰动，表现出持续的呼吸振荡。明中暗孤子可以通过对明孤子进行相位压印而产生。在介质速度下，两个孤子之间的碰撞是准弹性的，数值模拟了偶极$^{164}$ Dy BEC的三维平均场Gross-Pitaevskii方程，利用实际的相互作用参数证明了结果.
We demonstrate fast control of the interatomic interactions in a Bose-Einstein condensate by coherently coupling two atomic states with intra- and inter-state scattering lengths of opposite signs. We measure the elastic and inelastic scattering properties of the system and find good agreement with a theoretical model describing the interactions between dressed states. In the attractive regime, we observe the formation of bright solitons formed by dressed-state atoms. Finally, we study the response of the system to an interaction quench from repulsive to attractive values, and observe how the r…
Recent experimental and theoretical results show that weakly interacting atomic Bose-Bose mixtures with attractive interspecies interaction are stabilized by beyond-mean-field effects. Here we consider the peculiar properties of these systems in a strictly one-dimensional configuration, taking also into account the nontrivial role of spin-orbit and Rabi couplings. We show that when the value of inter- and intraspecies interaction strengths are such that mean-field contributions to the energy cancel, a self-bound bright soliton fully governed by quantum fluctuations exists. We derive the phase …
A study of bright matter-wave solitons of a cesium Bose-Einstein condensate (BEC) is presented. Production of a single soliton is demonstrated and dependence of soliton atom number on the interatomic interaction is investigated. Formation of soliton trains in the quasi one-dimensional confinement is shown. Additionally, fragmentation of a BEC has been observed outside confinement, in free space. In the end a double BEC production setup for studying soliton collisions is described.
Adopting a mean-field Gross-Pitaevskii description for a spinor polariton Bose-Einstein condensates under non-resonant pumping, we investigate the static and dynamical properties of dark-bright solitons. We derive analytically the equation of motion for the center of mass of the dark-bright soliton center, using the Hamiltonian approach. The resulting equation captures how the combination of the open-dissipative character and the spin degrees of freedom of a polariton Bose-Einstein condensate affects the properties of a dark-bright soliton, i.e. the dark-bright soliton relaxes by blending with…
This work deals with matter-wave bright soliton molecules in spin-1 Bose-Einstein condensates described by three-component Gross-Pitaevskii equations with non-autonomous nonlinearities that can be tuned by Feshbach resonance management. Notably, it portrays the possibility of generating bright bound soliton molecules with the help of an exact analytic solution under a controlled velocity resonance mechanism. Results show that these soliton molecules experience the effects of time-varying nonlinearities and modulate themselves during propagation by keeping their stable properties. Significantly…
The properties of nonlinear interference pattern between atomic bright solitons are characterized analytically, with the aid of exact solutions of dynamical equation in mean-field approximation. It is shown that relative velocity, relative phase, and nonlinear interaction strength can be measured from the interference pattern. The nonlinear interference properties are proposed to design atomic soliton interferometry in Bose-Einstein condensate. As an example, we apply them to measure gravity acceleration in a ultra-cold atom systems with a high precision degree. The results are also meaningful…
Synthetic spin-tensor-momentum coupling has recently been proposed to realize in atomic Bose-Einstein condensates. Here we study bright solitons in Bose-Einstein condensates with spin-tensor-momentum coupling and spin-orbit coupling. The properties and dynamics of spin-tensor-momentum-coupled and spin-orbit-coupled bright solitons are identified to be different. We contribute the difference to the different symmetries.
