Issue
EPL
Volume 84, Number 2, October 2008
Article Number 20012
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/84/20012
Published online 13 October 2008
EPL, 84 (2008) 20012
DOI: 10.1209/0295-5075/84/20012

Wave function engineering and circulating spin current in trapped Bose-Einstein condensates

J.-J. Song1, B. A. Foreman1, X.-J. Liu2, 3 and C. H. Oh3

1   Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
2   Department of Physics, Texas A&M University - College Station, TX 77843-4242, USA
3   Department of Physics, National University of Singapore - 2 Science Drive 3, Singapore 117542

edward.song@family.ust.hk

received 31 July 2008; accepted in final form 12 September 2008; published October 2008
published online 13 October 2008

Abstract
We propose a novel scheme to manipulate the wave function of a trapped Bose-Einstein condensate (BEC) by coupling its internal degrees of freedom to external optical vortex modes. The atom-light coupling induces an effective magnetic field on the center-of-mass motion, which drives the trapped BEC to vortex or non-vortex states determined by the effective magnetic flux. With a suitable external trap, the wave function of the optical mode can be fully written into the BEC and stored there. Based on this model, we also propose new techniques to generate static spin accumulation and circulating spin current in cold atomic systems.

PACS
03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations.
32.80.Qk - Coherent control of atomic interactions with photons.
72.25.Fe - Optical creation of spin polarized carriers.

© EPLA 2008