A rich variety of order parameter manifolds of multicomponent Bose-Einstein condensates (BECs) admit various kinds of topological excitations, such as fractional vortices, monopoles, skyrmions, and knots. In this paper, we discuss two topological excitations in spinor BECs: non-Abelian vortices and knots. Unlike conventional vortices, non-Abelian vortices neither reconnect themselves nor pass through each other, but create a rung between them in a topologically stable manner. We discuss the collision dynamics of non-Abelian vortices in the cyclic phase of a spin-2 BEC. In the latter part, we show that a knot, which is a unique topological object characterized by a linking number or a Hopf invariant [π3(S2) = Z], can be created using a conventional quadrupole magnetic field in a cold atomic system.
|Number of pages||8|
|Journal||Progress of Theoretical Physics|
|Issue number||SUPPL. 186|
|Publication status||Published - 2010 Dec 1|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)