Spin - orbital angular momentum coupled Bose-Einstein condensate

Kuei Sun, Chunlei Qu, Chuanwei Zhang

Mikkel F. Andersen, Pierre Cladé, Changhyun Ryu +3 more

Yu‐Ju Lin, Hongren Chen, Pao-Kang Chen +3 more

Eng Boon Ng, C. H. Raymond Ooi

We examine the use of Laguerre-Gaussian (LG) laser beams in the tripod scheme to create the coupling between spin and orbital angular momentum in a Bose–Einstein condensate (BEC) confined by a harmonic trap. We derive and solve the Gross-Pitaeskii equation numerically to obtain the density distribution of the BEC. Orbital angular momentum from the LG beam is transferred to the BEC, inducing the formation of a giant vortex at the BEC’s centre. The macroscopic flow of spinor BEC around the vortex leads to a persistent spin current in the BEC.

N.-C. Chiu, Yuki Kawaguchi, S-K Yip +1 more

Abstract Recently, stripe phases in spin–orbit coupled Bose–Einstein condensates (BECs) have attracted much attention since they are identified as supersolid phases. In this paper, we exploit experimentally reachable parameters and show that annular stripe phases with large stripe spacing and high stripe contrast can be achieved in spin–orbital-angular-momentum coupled (SOAMC) BECs. In addition to using Gross–Pitaevskii numerical simulations, we develop a variational ansatz that captures the essential interaction effects to first order, which are not present in the ansatz employed in previous literature. Our work should open the possibility towards directly observing stripe phases in SOAMC BECs in experiments.

Y.-J. Lin, Karina Jiménez-García, Ian B. Spielman