Figure 24.5 — Transfer of orbital angular momentum to a BEC Figure 24.5 — Transfer of orbital angular momentum to a BEC. Creation of vortices by the transfer of orbital angular momentum from a Laguerre–Gauss beam to the matter wave. (a) Absorption image of an atomic cloud with a doubly charged (+2h ̄ ) vortex; the core is larger than that for a single charged state. (b) Absorption image of a cloud resulting from the interference between a doubly charged state and a non-rotating state. (c) Calculated interference pattern between a doubly charged rotating state and a non-rotating state.Reprinted figure from Andersen et al., Phys. Rev. Lett. 97, 170406. Copyright (2006) by the American Physical Society.