Issue
EPL
Volume 86, Number 1, April 2009
Article Number 10008
Number of page(s) 4
Section General
DOI http://dx.doi.org/10.1209/0295-5075/86/10008
Published online 22 April 2009
EPL, 86 (2009) 10008
DOI: 10.1209/0295-5075/86/10008

Knotted vortex lines in spin-1 Bose-Einstein condensates

J. Liang1, X. Liu2 and Y. Duan1

1   Institute of Theoretical Physics, Lanzhou University - Lanzhou 730000, PRC
2   School of Mathematics and Statistics, University of Sydney - Sydney, NSW 2006, Australia

liangjunbeijing@yahoo.com.cn

received 10 January 2009; accepted in final form 15 March 2009; published April 2009
published online 22 April 2009

Abstract
Knotted vortex lines in the spin-1 Bose-Einstein condensates are studied. The Faddeev-Niemi model is considered, and it is found that naturally there exist topological vortex line structures in the condensates. We focus on the knotted vortex lines and examine their Faddeev-Niemi knot quantum number. It is shown that the Faddeev-Niemi number is identical to the sum of all the (self-)linking numbers of the knots family and is preserved during the branching processes of vortex lines.

PACS
03.75.Mn - Multicomponent condensates; spinor condensates.
47.32.cd - Vortex stability and breakdown.
02.10.Kn - Knot theory.

© EPLA 2009