Adiabatic population transfer in a multilevel system

Abstract

We report an experimental observation of coherent population transfer in a multilevel system by adiabatic following through a trapped state. Raman transitions between ground-state sublevels are induced by two partially overlapping o. + polarized laser beams, tuned to the hyperfine transition F =4~F'=4 of the cesium D2 line. An efficiency of more than 50%o is observed for the m+=+4 -+mz= -4 popula-

Two-dimensional sideband Raman cooling and Zeeman-state preparation in an optical lattice

“…We use the LU decomposition method. The numerical results are fitted by the formulae (7,8) very well. The fitting coefficients a, b, α and β depend on the angular momentum F and on the initial distribution among the vibrational levels.…”

“…Some of these problems are of a technical character and could be solved by different methods. For instance, atoms might be transfered from |F = 4, m = 4 to |F = 4, m = 0 without additional heating by the adiabatic passage technique [8], and the Ramsey region might be adequately isolated from the magnetic field. However, the problem of the light beams down the clock axis is more fundamental problem.…”

Limits of the separated-path Ramsey atom interferometer

“…Referring to the caesium relative decay rates shown in figure 7, we see that of this 35% loss, 5 24 (7%) will decay straight to F = 3, m F = 0 and stay there as incoherent background; 3 8 (13%) will decay to F = 3, m F = 1, 2 and not affect the interferometer, other than a drop in total signal; 5 12 (15%) will decay to various F = 4 states and get pumped around again, possibly resulting in another few per cent ending up in F = 3 or 4, m F = 0. The net result of all this optical pumping will be that after one 'out and straight back' AT, ∼60% of the initial atoms are returned to F = 4, m F = 0 coherently, ∼10% will be present as incoherent background in F = 3 or 4, m F = 0 and the rest will be lost from the states involved in the interferometer.…”

“…AT with delayed laser pulses has been demonstrated by a number of groups [5][6][7][8][9] as a method for coherently transferring population between internal atomic states and simultaneously imparting momentum to them. It relies on the atoms remaining in a dark state, a superposition of ground states which is decoupled from the excited state.…”

Raman coupling of Zeeman sublevels in an alkali-metal Bose-Einstein condensate

“…Further, a number of elegant experiments showing coherent control and creation of superpositions of Zeeman sublevels has been conducted with atomic beams of metastable neon [28,29,30]. We also note that the idea of using a stimulated Raman process to couple multiple groundstate Zeeman sublevels was previously explored theoretically [31] and that adiabatic passage between ground state sublevels of a cesium atomic beam has been demonstrated experimentally [32]. However, to our knowledge, our results here represent the first detailed treatment of Raman coupling between sublevels of the same groundstate Zeeman manifold in a way that takes into account both the excited state and the ground state level structure.…”