Transitions between Zeeman sublevels of an atom in a medium

Ju. A. Vdovin, Valery M. Yermachenko, V. K. Maskevitsh

Hong Yuan Ling, Yong Qing Li, Min Xiao

Huidong Kim, Hyok Sang Han, Jinsin Park +2 more

We report on a spectroscopic method to coherently drive a selective transition between two levels in a ladder system of equally spaced energy levels. A typical example of such a ladder system is a set of Zeeman sublevels in the same hyperfine level of a ground-state alkali-metal atom. The scheme is based on a stimulated Raman transition with a Zeeman sublevel belonging to the other hyperfine level as an intermediate state. We identify quantization conditions on a single-photon detuning and Rabi frequencies for either a $\ensuremath{\pi}/2$ or a $\ensuremath{\pi}$ transition between adjacent Zeeman sublevels without populating the intermediate state. We experimentally demonstrate the scheme using lithium atoms in an optical trap. Application of the scheme includes manipulating a pair of Zeeman sublevels as a quantum bit or probing Zeeman coherence established by coherent population trapping.

Takumi Minemoto, Kiyoshi Kakihara

The magnetic resonance between the Zeeman sublevels in the lower excited states 6 2 P 3/2 and 7 2 P 3/2 of 133 Cs atom has been observed in a medium magnetic field (15∼160 Gauss) by use of optical double resonance technique. From the positions of the resonance signals, the hyperfine coupling constants A , B , and the quadrupole moment Q have been evaluated as follows: A (6 2 P 3/2 )=50.45 MHz, B (6 2 P 3/2 )=-0.60 MHz, A (7 2 P 3/2 )=16.55 MHz, B (7 2 P 3/2 )=-0.20 MHz, and Q =-0.0045×10 -24 cm 2 . The effects of the collisions with noble gas atoms (He, Ne, and Ar) on the resonance signals have been observed. For the resonance signals between the Zeeman sublevels | F =3, m F =-2>↔|3, -3> in 6 2 P 3/2 state, |4, -3>↔|4, -4>, |4, -2>↔|4, -3>, |5, -4>↔|5, -5>, and |5, -2>↔|5, -3> in 7 2 P 3/2 state, the crosssections of the collisional broadening have been evaluated from variations of the line widths.

J.M. Winter

Bo Wang, Yanxu Han, Jintao Xiao +5 more

We demonstrate a simple, all-optical technique to prepare and determine the desired internal quantum states in multi-Zeeman-sublevel atoms. By choosing appropriate coupling and pumping laser beams, atoms can be easily prepared in a desired Zeeman sublevel with high purity or in any chosen ground-state population distributions (spin-polarized quantum-state engineering). The population distributions or state purities of such prepared atomic states can be determined by using a weak, circularly polarized probe beam due to differences in transition strengths among different Zeeman sublevels. This technique will have potential impact on quantum-information processing in multilevel atomic systems.