Precursor phenomena of nucleations of quantized vortices in the presence of a uniformly moving obstacle in Bose-Einstein condensates

Abstract

We investigate excitations and fluctuations of Bose-Einstein condensates in a two-dimensional torus with a uniformly moving Gaussian potential by solving the Gross-Pitaevskii equation and the Bogoliubov equation. The energy gap $\Delta$ between the current-flowing metastable state (that reduces to the ground state for sufficiently slowly-moving potential) and the first excited state vanishes when the moving velocity $v$ of the potential approaches a critical velocity v_c(>0). We find a scaling law $\Delta \propto (1-|v|/v_c{)}^{1/4}$, which implies that a characteristic time scale diverges toward the critical velocity. Near the critical velocity, we show that low-energy local density fluctuations are enhanced. These behaviors can be regarded as precursor phenomena of the vortex nucleation.

7 pages, 3 figures

References in corpus (5)

• Driving phase slips in a superfluid atom circuit with a rotating weak link
• Mean-field and stability analysis of two-dimensional flowing soft-core bosons modeling a supersolid
• Critical Rotation of an Annular Superfluid Bose Gas
• Critical velocity for a toroidal Bose-Einstein condensate flowing through a barrier
• Absence of Anomalous Tunneling of Bogoliubov Excitations for Arbitrary Potential Barrier under the Critical Condensate Current

Cited by in corpus (2)

• Metastability, excitations, fluctuations, and multiple-swallowtail structures of a superfluid in a Bose-Einstein condensate in the presence of a uniformly moving defect
• Superfluid Field response to Edge dislocation motion