Sindelka Milan, Moiseyev Nimrod
Department of Chemistry and Minerva Center of Nonlinear Physics in Complex Systems, Technion-Israel Institute of Technology, Haifa 32000, Israel.
J Phys Chem A. 2006 Apr 27;110(16):5561-71. doi: 10.1021/jp057120j.
We study a general problem of the translational/rotational/vibrational/electronic dynamics of a diatomic molecule exposed to an interaction with an arbitrary external electromagnetic field. The theory developed in this paper is relevant to a variety of specific applications, such as alignment or orientation of molecules by lasers, trapping of ultracold molecules in optical traps, molecular optics and interferometry, rovibrational spectroscopy of molecules in the presence of intense laser light, or generation of high order harmonics from molecules. Starting from the first quantum mechanical principles, we derive an appropriate molecular Hamiltonian suitable for description of the center of mass, rotational, vibrational, and electronic molecular motions driven by the field within the electric dipole approximation. Consequently, the concept of the Born-Oppenheimer separation between the electronic and the nuclear degrees of freedom in the presence of an electromagnetic field is introduced. Special cases of the dc/ac-field limits are then discussed separately. Finally, we consider a perturbative regime of a weak dc/ac field, and obtain simple analytic formulas for the associated Born-Oppenheimer translational/rotational/vibrational molecular Hamiltonian.
我们研究了双原子分子在与任意外部电磁场相互作用时的平动/转动/振动/电子动力学的一般问题。本文所发展的理论适用于多种具体应用，例如通过激光使分子取向或定向、在光阱中捕获超冷分子、分子光学与干涉测量、在强激光存在下分子的振转光谱，或者从分子产生高次谐波。从第一量子力学原理出发，我们推导了一个合适的分子哈密顿量，适用于在电偶极近似下描述由场驱动的分子质心、转动、振动和电子运动。因此，引入了在存在电磁场的情况下电子与核自由度之间的玻恩 - 奥本海默分离概念。然后分别讨论了直流/交流场极限的特殊情况。最后，我们考虑弱直流/交流场的微扰 regime，并得到了相关的玻恩 - 奥本海默平动/转动/振动分子哈密顿量的简单解析公式。 （注：原文中“perturbative regime”直译为“微扰 regime”，这里“regime”可结合语境理解为“情况、状态等”，整体意思是在弱直流/交流场这种微扰的情况下）
