Two-photon excitation dynamics in bound two-body Coulomb systems including ac Stark shift and ionization
Two-photon excitation dynamics in bound two-body Coulomb systems including ac Stark shift and ionization
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DOI：
10.1103/physreva.73.052501
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发表时间：
2006-05-01
影响因子：
2.9
通讯作者：
Agarwal, G. S.
中科院分区：
文献类型：
--
作者：
Haas, M.;Jentschura, U. D.;Agarwal, G. S.
在双光子跃迁的高精度测量中移动共振线的主要系统效应之一是动态（ac）斯塔克位移。对于合适的激光频率，交流斯塔克位移获得一个虚部，该虚部对应于电子共振单光子电离成连续态的速率。在当前的光谱精度水平上，必须很好地理解控制原子双光子激发过程的基本时间相关量子动力学，相关考虑因素是本文的主题。为了说明瞬态状态的基本机制，我们研究了密度矩阵形式中的群体动力学的可分析求解的模型场景，并详细描述了如何推广相应的运动方程以供单独的实验使用。我们还计算了束缚二体库仑系统中双光子 S-S 和 S-D 跃迁的动态斯塔克位移以及相应的双光子跃迁矩阵元素。特别是，我们研究了 1S 基态或亚稳态 2S 态作为低能态的跃迁，以及具有 n 的状态。
One of the dominant systematic effects that shift resonance lines in high-precision measurements of two-photon transitions is the dynamic (ac) Stark shift. For suitable laser frequencies, the ac Stark shift acquires an imaginary part which corresponds to the rate of resonant one-photon ionization of electrons into a continuum state. At the current level of spectroscopic accuracy, the underlying time-dependent quantum dynamics governing the atomic two-photon excitation process must be well understood, and related considerations are the subject of the present paper. In order to illustrate the basic mechanisms in the transient regime, we investigate an analytically solvable model scenario for the population dynamics in the density matrix formalism and describe in detail how to generalize the corresponding equations of motion for individual experimental use. We also calculate the dynamic Stark shift for two-photon S-S and S-D transitions in bound two-body Coulomb systems and the corresponding two-photon transition matrix elements. In particular, we investigate transitions for which the 1S ground state or alternatively the metastable 2S state acts as the lower-energy state, and for which states with n