We present a theoretical study of the rotational dynamics of asymmetry top molecules in an electric field and a parallel non-resonant linearly polarized laser pulse. The time-dependent Schrödinger equation is solved within the rigid rotor approximation. Using the benzonitrile molecule as prototype, we investigate the field-dressed dynamics for experimentally accessible field configurations and compare these results to the adiabatic predictions. We show that for an asymmetric top molecule in parallel fields, the formation of the pendular doublets and the avoided crossings between neighboring levels are the two main sources of non-adiabatic effects. We also provide the field parameters under which the adiabatic dynamics would be achieved.
We present an analytical approach to construct the Lie algebra of finite-dimensional subsystems of the driven asymmetric top rotor. Each rotational level is degenerate due to the isotropy of space, and the degeneracy increases with rotational excitation. For a given rotational excitation, we determine the nested commutators between drift and drive Hamiltonians using a graph representation. We then generate the Lie algebra for subsystems with arbitrary rotational excitation using an inductive argument.
Theoretical description of mixed-field orientation of asymmetric top molecules: a time-dependent study
通过求解含时薛定谔方程,对倾斜电场和非共振线偏振激光脉冲作用下非对称陀螺分子的混合场取向进行了理论研究.在此框架下,我们计算了苯腈(C $_7$ H $_5$ N)的选态分子束的混合场取向,并与实验结果进行了比较[J. L. Hansen等人,A 83,023406(2011)],并且利用我们先前的时间无关描述[J.J.Omiste等人,13,18815(2011)]。对于一个激发转动态,我们研究了混合场实验中使用的几种场配置的场修饰动力学。详细分析了非绝热现象及其对转动动力学的影响。
We propose and computationally study a method for simultaneously orienting the angular momentum of asymmetric top molecules along: 1) a laboratory-fixed direction; 2) the molecular intermediate moment of inertia axis; 3) the laser field wavevector. For this purpose we utilize a coherent control scheme in which a tailored-pulse optical centrifuge populates rotational states with well defined projections of the total angular momentum onto molecular axes. Appropriately time-shaped optical centrifuge pulses can leave the rotational wavepacket in peculiar rotational coherences which lead to a good …