Population redistribution of atomic ground-term sublevels during optical pumping at multiphoton transitions

Lei Han, Fang Fang, Yani Zuo +5 more

In this paper, a new optical pumping method, redistributing the atom populations among the Zeeman magnetic sublevels of the ground state |F=3> is proposed as the state preparation process to improve the signal to noise ratio (SNR) of the atomic fountain clock with a larger atom population on the |F=3, mF=0>clock state. A preliminary experimental result of state preparation efficiency exceeding 60% is obtained on the NIM6 cesium (Cs) fountain clock.

A.S. Shumovsky, E.I. Aliskenderov, Fam Le Kien

Hossein Davoodi Yeganeh, Zahra Shaterzadeh‐Yazdi

Optical pumping is a technique for engineering atomic-sublevel population of desired atoms. We investigate the population evolution of Cesium atoms by employing Liouville equation. For this purpose, we apply a circularly polarized light at a frequency suitable for electronic transition from ground states to excited states and calculate the relaxation rate, repopulation, and population evolution of the Cesium Zeeman sublevels. For engineering the sublevel population after optical pumping, we employ a radiofrequency (RF) field and consider the effect of RF field in Liouville equation. With this approach, we are able to prepare desired distribution of the population in the atomic sublevels with high efficiency, which can be employed in different optical experiments.

V. G. Domelunksen, I. V. Zhurkin, A. Yu. Nikolaev +1 more

Luo Jun, Xianping Sun, Zeng Xi-zhi +1 more

Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti:sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved through hyperfine interactions between electrons and nuclei. The steady-state population distribution in the hyperfine Zeeman sublevels of the ground state is detected by using a tunable diode laser. Furthermore, the state population transfer among the hyperfine Zeeman sublevels, which results from the collision-induced modification δ a ( S · I ) of the hyperfine interaction of Cs in the ground state due to stochastic collisions between Cs atoms and buffer-gas molecules, is studied at different buffer-gas pressures. The experimental results show that high-field optical pumping and the small change δ a ( S · I ) of the hyperfine interaction can strongly cause the state population transfer and spin-state interchange among the hyperfine Zeeman sublevels. The calculated results maybe explain the steady-state population in hyperfine Zeeman sublevels in terms of rates of optical-pumping, electron-spin flip, nuclear spin flip, and electron-nuclear spin flip-flop transitions among the hyperfine Zeeman sublevels of the ground state of Cs atoms. This method may be applied to the nuclear-spin-based solid-state quantum computation.

A. O. Melikyan, R. M. Movsesyan