Creation and Detection of Skyrmions in a Bose-Einstein Condensate

Abstract

We present the first experimental realization and characterization of two-dimensional Skyrmions and half-Skyrmions in a spin-2 Bose-Einstein condensate. The continuous rotation of the local spin of the Skyrmion through an angle of pi (and half-Skyrmion through an angle of pi/2) across the cloud is confirmed by the spatial distribution of the three spin states as parametrized by the bending angle of the l vector. The winding number w = (0,1,2) of the internal spin states comprising the Skyrmions is confirmed through matter-wave interference.

Topological interface physics of defects and textures in spinor Bose-Einstein condensates

“…Interface physics has been studied in two-component BEC systems, for example, in the context of vortex bifurcation at energetically established interfaces in the phase-separation regime [68,69] and interface collisions [19]. There is a rapid parallel experimental development, exemplified by preparation of coreless vortices and related textures [70][71][72][73], as well as observations of singular vortices produced in phase transitions [74], and of spin-texture formation [75][76][77]. Furthermore, trapping of ultracold atoms in artificial gauge-field potentials [78] was recently realized experimentally [79,80].…”

Quasi-two-dimensional Skyrmion lattices in a chiral nematic liquid crystal

“…In the mid-1990 s Skyrmions were predicted and observed in quantum Hall devices [2][3][4] , with the realization that quantum effects are best understood in terms of topological features. Later, spinor Bose-Einstein condensates were shown to accommodate Skyrmions due to the internal spin degrees of freedom [5][6][7] . More recently, great attention has been paid to Skyrmions in helical ferromagnets 8 , such as MnSi 4,9,10 and Fe 1-x Co x Si 11,12 , characterized by a lack of inversion symmetry (chirality) and the presence of DzyalonshinskiiMoriya spin-orbit interaction.…”

Inducing vortices in a Bose-Einstein condensate using holographically produced light beams

“…This spin texture, shown in Fig. 2(c), describes a skyrmion [14]. Skrymions have been used as a model for baryonic particles in nuclear physics [32,33].…”

“…In biophysics and micromechanics this torque has been proposed to be utilizable in driving molecular motors and micromachines, which can at the same time be trapped at the location of the singularity, where the beam intensity has to vanish [1,[8][9][10]. Also, in the field of ultracold atoms, direct transfer of OAM from light to atoms in an ultracold gas cloud offers interesting possibilities [11][12][13][14].…”

“…A Raman process addresses specific atomic spin states. It is thus possible to imprint the intensity and phase information contained in the Raman beams onto the atomic spin degree of freedom, creating a spin vortex [12][13][14]30].…”