Magic polarization for optical trapping of atoms without Stark-induced dephasing.
We demonstrate that the differential ac-Stark shift of a Zeeman-sensitive ground hyperfine transition in an optical trap can be eliminated by using properly polarized trapping light. We use the vector polarizability of an alkali-metal atom to produce a polarization-dependent ac-Stark shift that resembles a Zeeman shift. We study a transition from the |2S1/2,F=2,mF=-2> to the |2S1/2,F=1,mF=-1> state of 7Li to observe 0.59±0.02  Hz linewidth with interrogation time of 2 s and 0.82±0.06  s coherence time of a superposition state. Implications of the narrow linewidth and the long coherence time for precision spectroscopy and quantum information processing using atoms in an optical lattice are discussed.
Department of Physics, Korea University, Seoul 136-713, Korea.
Huidong
H
Kim
Department of Physics, Korea University, Seoul 136-713, Korea.
Hyok Sang
HS
Han
Department of Physics, Korea University, Seoul 136-713, Korea.
D
D
Cho