Manifestation of Superfluidity in Atom-Number-Imbalanced Two-Component Bose-Einstein Condensates
Abstract
Superfluid and dissipative regimes in the dynamics of a two-component quasi-one-dimensional Bose-Einstein condensate (BEC) with unequal atom numbers in the two components have been explored. The system supports localized waves of the symbiotic type owing to the same-species repulsion and cross-species attraction. The minority BEC component moves through the majority component and creates excitations. To quantify the emerging excitations, we introduce a time-dependent function called disturbance. Through numerical simulations of the coupled Gross-Pitaevskii equations with periodic boundary conditions, we have identified a critical velocity of the localized wave, above which a transition from the superfluid to dissipative regime occurs, as evidenced by a sharp increase in the disturbance function. The factors responsible for the discrepancy between the actual critical velocity and the speed of sound, expected from theoretical arguments, have been discussed.
- Publication:
-
Symmetry
- Pub Date:
- July 2024
- DOI:
- 10.3390/sym16070910
- arXiv:
- arXiv:2406.07204
- Bibcode:
- 2024Symm...16..910A
- Keywords:
-
- quantum gas;
- superfluidity;
- critical velocity;
- numerical simulation;
- 67.85.De;
- 03.75.Kk;
- 05.30.Jp;
- Condensed Matter - Quantum Gases
- E-Print:
- 11 pages, 4 figures. Submitted to a special issue of the journal Symmetry: "Nonlinear Science and Numerical Simulation with Symmetry"