Collisions of Dark Solitons in Elongated Bose-Einstein Condensates

Abstract

We present experimental data showing the head-on collision of dark solitons generated in an elongated Bose-Einstein condensate. No discernable interaction can be recorded, in full agreement with the fundamental theoretical concepts of solitons as mutually transparent quasiparticles. Our soliton generation technique allows for the creation of solitons with different depths; hence, they can be distinguished and their trajectories be followed. Simulations of the 1D-Gross-Pitaevskii equation have been performed to compare the experiment with a mean-field description.

Long-range sound-mediated dark-soliton interactions in trapped atomic condensates

“…Under current experimental conditions this identity reversal may not be observable, as more oscillations are required than have been observed up until now [6][7][8], and one would additionally need to significantly minimize the region where the potential becomes anharmonic. However, experiments should be able to detect that the presence of a second soliton in a condensate confined in an appropriate double well geometry has a stabilizing effect.…”

“…Recent experiments have been able to generate appropriate low-temperature conditions in quasi-1D geometries enabling the observation of one or more (undamped) dark soliton oscillations in a harmonically-confined condensate [6][7][8] as predicted at the mean field level [15][16][17]. In general, the presence of the axial confinement in these experiments breaks the integrability of the system, rendering the soliton unstable to sound emission along its axis of propagation, inducing it to decay [15,18,19].…”

“…Dark solitons are localized waves propagating within a background medium, and are characterized by a dip of the density and a phase slip [2]. They have recently become a topic of intense research in weakly-interacting atomic BoseEinstein condensates [3], being routinely generated in a number of experiments, both in a controlled manner [4][5][6][7][8][9] and as a result of dynamical processes [10][11][12][13][14].…”

Multiple dark-bright solitons in atomic Bose-Einstein condensates

“…The latter works have finally realized oscillating, and even interacting, robust dark solitons in atomic BECs. This has been achieved by means of various techniques, including phase-imprinting and density engineering [10][11][12], matter-wave interference [13,14], and dragging localized defects through the BECs [15].…”

Multiple Fluxon Analogues and Dark Solitons in Linearly Coupled Bose–Einstein Condensates

“…The dynamics of a dark soliton in BECs in the uncoupled system with magnetic trap has been considered before theoretically [22,23] (see also [24] and references therein) and experimentally [25,27,28,26,29]. Interesting phenomena on the collective behavior of a quantum degenerate bosonic gas, such as soliton oscillations [28,26,25] and frequency shifts due to soliton collisions [29] were observed. A theoretical analysis based on variational formulation was developed in [30,31] that is in good agreement with numerics as well as with experiments (see, e.g., [32,33]).…”