Harmonically trapped attractive and repulsive spin-orbit and Rabi coupled Bose-Einstein condensates

TL;DR

This paper numerically studies the ground states of spin-orbit and Rabi coupled Bose-Einstein condensates in harmonic traps, revealing effects on density profiles, multi-peak structures, and collapse thresholds for both attractive and repulsive interactions.

Contribution

It provides new insights into how harmonic trapping, spin-orbit, and Rabi couplings influence the ground state properties of BECs with both interaction types.

Findings

Harmonic traps reduce multi-peak structures and increase density.

Increased SO coupling leads to less dense, multi-peak condensates in repulsive interactions.

Rabi coupling increases density with stable multi-peak numbers.

Abstract

Numerically we investigate the ground state of effective one-dimensional spin-orbit (SO) and Rabi coupled two pseudo-spinor Bose-Einstein condensates (BECs) under the effect of harmonic traps. For both signs of the interaction, density profiles of SO and Rabi coupled BECs in harmonic potentials, which simulate a real experimental situation are obtained. The harmonic trap causes a strong reduction of the multi-peak nature of the condensate and it increases its density. For repulsive interactions, the increase of SO coupling results in an uncompressed less dense condensate and with increased multi-peak nature of the density. The increase of Rabi coupling leads to a density increase with an almost constant number of multi-peaks. For both signs of the interaction and negative values of Rabi coupling, the condensate develops a notch in the central point and it seems to a dark-in-bright soliton. In the case of the attractive nonlinearity, an interesting result is the increase of the collapse threshold under the action of the SO and Rabi couplings.