Topological defect dynamics of vortex lattices in Bose-Einstein condensates

Abstract

Vortex lattices in rapidly rotating Bose-Einstein condensates are systems of topological excitations that arrange themselves into periodic patterns. Here we show how phase-imprinting techniques can be used to create a controllable number of defects in these lattices and examine the resulting dynamics. Even though we describe our system using the mean-field Gross-Pitaevskii theory, the full range of many particle effects among the vortices can be studied. In particular we find the existence of localized vacancies that are quasi-stable over long periods of time, and characterize the effects on the background lattice through use of the orientational correlation function, and Delaunay triangulation.

Chaotic few-body vortex dynamics in rotating Bose-Einstein condensates

“…However, for smaller rotation strengths other configurations are known [41] and we will concentrate on the regime where four vortices appear in the ground state. While the direction of rotation of the individual vortices is usually the same as that of the applied external rotation, this can be changed by phase imprinting [28].…”

“…1(b)) will reverse the direction of circulation of that vortex. To annihilate or change the direction of circulation of a vortex through phase imprinting, the imprinted phase mask must be centred on a vortex in the lattice close to the vortex core at a distance of less than twice the condensate healing length [28].…”

“…One way to capitalise on this stability and generate repeatable and well controlled initial conditions is to engineer lattice defects by applying the technique of phase imprinting. Phase imprinting can be used to control both the number and location of defects in vortex lattices [28] and is also experimentally feasible [29]. Phase imprint-ing has been applied in a variety of BEC experiments, ranging from transferring orbital angular momentum to atoms from a Laguerre-Gaussian beam [30,31], to using a pulsed light shift with a tailored intensity pattern to create a soliton [32], vortex [33], or states with quantized circulation [34].…”

Vortex patterns of atomic Bose-Einstein condensates in a density-dependent gauge potential

“…Vortices central role in superfluidity continues to attract theoretical and experimental interest in the macroscopic dynamics of these excitations. Early work focussed on studying the fundamental properties of the rotating system [13][14][15], while more recent work has focussed on understanding the effect of anisotropic trapping [16], vortex lattice [17,18], and chaotic [19] dynamics. Focus has also been on the structure and dynamics of vortices in condensates at finite temperature including non-equilibrium effects [20,21], multi-component systems which have been shown to possess a rich vortex physics [23][24][25][26][27][28] and the on-going quest to understand quantum turbulence [29,30].…”

Synthetic superfluid chemistry with vortex-trapped quantum impurities

“…Understanding the complex dynamics of superfluids is assisted by knowledge of the few-body dynamics of vortices, in particular the realization of vortex dipoles [33] continues to provide important information [34,35], as well as the observation of solitonic vortices [36] in elongated superfluids. Multiple vortex states are generated by rotating the atomic cloud [37][38][39], leading at large rotation to the formation of the Abrikosov vortex lattice [40,41].…”