Ultracold cesium atoms are stored in a novel dipole-force trap, which
provides long storage times of spin polarization and facilitates easy
Stern-Gerlach selection. The trap consists of a far red-detuned standing
light wave, oriented vertically in the field of gravity.
By comparing the trapping of a single magnetic substate (F=4, mF=0)
with the simultaneous storage of all sublevels,
we measure the decay of spin polarization that results from photon
scattering
of trap light.
We furthermore observe spin precession in an optically induced “fictitious
magnetic field”
