  Vortices were imprinted in a Bose-Einstein condensate using topological
phases. Sodium condensates held in a Ioffe-Pritchard magnetic trap were
transformed from a non-rotating state to one with quantized circulation by
adiabatically inverting the magnetic bias field along the trap axis. Using
surface wave spectroscopy, the axial angular momentum per particle of the
vortex states was found to be consistent with $2\hbar$ or $4\hbar$, depending
on the hyperfine state of the condensate.
