Transmission and reflection of Bose-Einstein condensates incident on a Gaussian tunnel barrier

Abstract

We investigate how Bose-Einstein condensates, whose initial state is either irrotational or contains a single vortex, scatter off a one-dimensional Gaussian potential barrier. We find that for low atom densities the vortex structure within the condensate is maintained during scattering, whereas at medium and high densities, multiple additional vortices can be created by the scattering process, resulting in complex dynamics and disruption of the atom cloud. This disruption originates from two different mechanisms associated respectively with the initial rotation of the atom cloud and the interference between the incident and reflected matter waves. We investigate how the reflection probability depends on the vorticity of the initial state and on the incident velocity of the BoseEinstein condensate. To interpret our results, we derive a general analytical expression for the reflection coefficient of a rotating Bose-Einstein condensate that scatters off a spatially-varying one-dimensional potential.

A Rapidly Expanding Bose-Einstein Condensate: An Expanding Universe in the Lab

“…This standing wave has nodes in the atomic density with corresponding π phase jumps, effectively imprinting a dark soliton onto the BEC [46,47]. This process is analogous to the creation of solitons upon Bragg reflection in an optical lattice [48] or reflection of a condensate off of a tunnel barrier [49]. (Unfortunately, due to imaging limitations, we are unable to resolve solitons or other similarly-sized structures in the experiment.…”

Impact of the transverse direction on the many-body tunneling dynamics in a two-dimensional bosonic Josephson junction

“…Spagnolli et al reported a detailed study of the transition from Rabi to plasma oscillations by crossing over from the attractive to repulsive inter-atomic interaction in terms of the evolution of atomic imbalance 43 . Moreover, in two dimensions (2D), the tunneling dynamics of trapped vortices were studied using Gross–Pitaevskii mean-field model in 2D superfluids 44 , in an harmonic potential with a Gaussian potential barrier 45 , and between two pinning potentials 46 . Salgueiro et al proposed a method of generating replicas of a vortex state in a double-well potential formed by conjoining two Gaussian potentials using the mean-field approach 47 .…”

Influence of a dark soliton on the reflection of a Bose–Einstein condensate by a square barrier

“…Quantum reflections of vortices in BECs incident on a solid surface and a Gaussian tunnel barrier were studied in Refs. [22,23], where the authors focused on the dynamical excitations induced by interatomic interaction and gave the phase diagram of the vortex stability. The dynamics of one-dimensional dark-solitons in inhomogeneous BECs when incident on a potential gradient is studied in Ref.…”