English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the 1D dynamics of dark-dark solitons in the miscible regime of twodensity-coupled Bose-Einstein condensates having repulsive interparticleinteractions within each condensate ($g>0$). By using an adiabatic perturbationtheory in the parameter $g_{12}/{g}$, we show that, contrary to the case of twosolitons in scalar condensates, the interactions between solitons areattractive when the interparticle interactions between condensates arerepulsive $g_{12}>0$. As a result, the relative motion of dark solitons withequal chemical potential $\mu$ is well approximated by harmonic oscillations ofangular frequency $w_r=(\mu/\hbar)\sqrt{({8}/{15}){g_{12}}/{g}}$. We also showthat in finite systems, the resonance of this anomalous excitation mode withthe spin density mode of lowest energy gives rise to alternating dynamicalinstability and stability fringes as a function of the perturbative parameter.In the presence of harmonic trapping (with angular frequency $\Omega$) thesolitons are driven by the superposition of two harmonic motions at a frequencygiven by $w^2=(\Omega/\sqrt{2})^2+w_r^2$. When $g_{12}<0$, these twooscillators compete to give rise to an overall effective potential that can beeither single well or double well through a pitchfork bifurcation. All ourtheoretical results are compared with numerical solutions of theGross-Pitaevskii equation for the dynamics and the Bogoliubov equations for thelinear stability. A good agreement is found between them.

Dark-dark-soliton dynamics in two density-coupled Bose-Einstein condensates