Issue
EPL
Volume 85, Number 2, January 2009
Article Number 20002
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/85/20002
Published online 30 January 2009
EPL, 85 (2009) 20002
DOI: 10.1209/0295-5075/85/20002

Spin structure and critical nucleation frequency of fractionalized vortices in 2D topologically ordered superfluids of cold atoms

Jun Liang Song and Fei Zhou

Department of Physics and Astronomy, The University of British Columbia - Vancouver, B. C., V6T1Z1 Canada

jlsong@phas.ubc.ca

received 22 August 2008; accepted in final form 15 December 2008; published January 2009
published online 30 January 2009

Abstract
We have studied spin structures of fluctuation-driven fractionalized vortices and topological spin order in 2D nematic superfluids of cold sodium atoms. Our Monte Carlo simulations suggest a softened$\pi $-spin disclination structure in a half-quantum vortex when spin correlations are short ranged; in addition, calculations indicate that a unique non-local topological spin order emerges simultaneously as cold atoms become a superfluid below a critical temperature. We have also estimated fluctuation-dependent critical frequencies for half-quantum vortex nucleation in rotating optical traps and discussed probing these excitations in experiments.

PACS
03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations.
03.75.Mn - Multicomponent condensates; spinor condensates.
03.75.Nt - Other Bose-Einstein condensation phenomena.

© EPLA 2009