Arango Carlos A, Kennerly William W, Ezra Gregory S
Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
J Chem Phys. 2005 May 8;122(18):184303. doi: 10.1063/1.1888574.
We investigate the classical and quantum mechanics of diatomic molecules in noncollinear (tilted) static electric and nonresonant linearly polarized laser fields. The classical diatomic in tilted fields is a nonintegrable system, and we study the phase space structure for physically relevant parameter regimes for the molecule KCl. While exhibiting low-energy (pendular) and high-energy (free-rotor) integrable limits, the rotor in tilted fields shows chaotic dynamics at intermediate energies, and the degree of classical chaos can be tuned by changing the tilt angle. We examine the quantum mechanics of rotors in tilted fields. Energy-level correlation diagrams are computed, and the presence of avoided crossings quantified by the study of nearest-neighbor spacing distributions as a function of energy and tilting angle. Finally, we examine the influence of classical periodic orbits on rotor wave functions. Many wave functions in the tilted field case are found to be highly nonseparable in spherical polar coordinates. Localization of wave functions in the vicinity of classical periodic orbits, both stable and unstable, is observed for many states.
我们研究了双原子分子在非共线（倾斜）静电场和非共振线偏振激光场中的经典力学和量子力学。倾斜场中的经典双原子分子是一个不可积系统，我们研究了分子KCl在物理相关参数区域的相空间结构。虽然在倾斜场中的转子在低能量（摆动）和高能量（自由转子）时表现出可积极限，但在中间能量时显示出混沌动力学，并且经典混沌程度可以通过改变倾斜角来调节。我们研究了倾斜场中转子的量子力学。计算了能级相关图，并通过研究作为能量和倾斜角函数的最近邻间距分布来量化避免交叉的存在。最后，我们研究了经典周期轨道对转子波函数的影响。发现在倾斜场情况下，许多波函数在球极坐标中高度不可分离。对于许多状态，观察到波函数在经典周期轨道（包括稳定和不稳定轨道）附近的局域化。
