Correlated dynamics of collective droplet excitations in a one-dimensional harmonic trap

We address the existence and dynamics of one-dimensional harmonically confined quantum droplets ap-pearing in two-component mixtures by deploying a nonperturbative approach. We find that, in symmetric homonuclear settings, beyond-Lee-Huang-Yang correlations result in flat-top droplet configurations for either decreasing intercomponent attraction or larger atom number. Asymmetric mixtures feature spatial mixing among the involved components with the more strongly interacting or heavier one exhibiting flat-top struc-tures. Applying quenches on the harmonic trap we trigger the lowest-lying collective droplet excitations. The interaction-dependent breathing frequency, being slightly reduced in the presence of correlations, shows a decreasing trend for stronger attractions. Semianalytical predictions are also obtained within the Lee-Huang -Yang framework. For relatively large quench amplitudes the droplet progressively delocalizes and higher-lying motional excitations develop in its core. Simultaneously, enhanced intercomponent entanglement and long-range two-body intracomponent correlations arise. In sharp contrast, the dipole motion remains robust irrespective of the system parameters. Species-selective quenches lead to a correlation-induced dephasing of the droplet or to irregular dipole patterns due to intercomponent collisions.

Automated summary

We study one-dimensional harmonically confined quantum droplets in two-component mixtures using a nonperturbative approach. In symmetric homonuclear settings, beyond-Lee-Huang-Yang correlations result in flat-top droplet configurations for decreasing intercomponent attraction or larger atom number. Asymmetric mixtures feature spatial mixing and the more strongly interacting or heavier component exhibits flat-top structures. Quenches on the harmonic trap trigger the lowest-lying collective droplet excitations, and the interaction-dependent breathing frequency shows a decreasing trend for stronger attractions. Predictions within the Lee-Huang-Yang framework are obtained. Relatively large quench amplitudes cause delocalization of the droplet, higher-lying motional excitations in its core, enhanced intercomponent entanglement, and long-range correlations. In contrast, the dipole motion remains robust. Species-selective quenches lead to dephasing or irregular dipole patterns due to intercomponent collisions.