利用超短脉冲laser定向耦合量子转子

Quantum dynamics of a planar rotor driven by suddenly switched combined aligning and orienting interactions

We investigate, both analytically and numerically, the quantum dynamics of a planar (2D) rigid rotor subject to suddenly switched-on or switched-off concurrent orienting and aligning interactions. We find that the time-evolution of the post-switch populations as well as of the expectation values of orientation and alignment reflects the spectral properties and the eigensurface topology of the planar pendulum eigenproblem established in our earlier work [Frontiers in Physics 2, 37 (2014); Eur. Phys. J. D 71, 149 (2017)]. This finding opens the possibility to examine the topological properties o…

Dynamics of polar polarizable rotors acted upon by unipolar electromagnetic pulses: From the sudden to the adiabatic regime

We study, analytically as well as numerically, the dynamics that arises from the interaction of a polar polarizable rigid rotor with single unipolar electromagnetic pulses of varying length, $Δτ$, with respect to the rotational period of the rotor, $τ_r$. In the sudden, non-adiabatic limit, $Δτ\ll τ_r$, we derive analytic expressions for the rotor's wavefunctions, kinetic energies, and field-free evolution of orientation and alignment. We verify the analytic results by solving the corresponding time-dependent Schrödinger equation numerically and extend the temporal range of the interactions co…

Optimal control of interacting quantum systems based on the first-order Magnus approximation: Application to multiple dipole-dipole coupled molecular rotors

We develop a methodology for performing approximate optimal control simulations for quantum systems with multiple interacting degrees of freedom. The quantum dynamics are modeled using the first-order Magnus approximation in the interaction picture, where the interactions between different degrees of freedom are treated as the perturbation. We present a numerical procedure for implementing this approximation, which leverages the separability of the zeroth-order time evolution operator and the pairwise nature of common interactions for a reduced computational cost. This formulation of the first…

Echo Spectroscopy in multi-level quantum-mechanical rotors

The rotational echo response of molecules is found to strongly depend on the delay between the two ultrashort laser pulses, as opposed to two-level systems. We study this dependence experimentally and theoretically and show that by judicious control of the 2nd pulse intensity, 'rotational echo spectroscopy' in a multi-level molecular system becomes possible.

利用超短脉冲laser实现混合分子的量子共振、Anderson定域和选择性操纵

Quantum resonance, Anderson localisation and selective manipulations in molecular mixtures by ultrashort laser pulses

我们证明，目前的激光技术用于无场分子排列通过级联的拉曼旋转跃迁允许观察长期讨论的非线性量子现象的动态周期性踢转子。这包括在量子共振条件附近的吸收能量的缩放和角动量中的安德森样局部化。基于这些发现，我们提出了一种新的方法，可调谐的选择性旋转激发和排列的分子混合物，使用列车的短激光脉冲。我们通过将其应用于两种氮同位素（14N2和15N2）的混合物来证明这种方法的效率，并表明即使在室温下也可能具有很强的选择性。

laser分子转子中量子局域化和经典扩散的控制

Control of quantum localization and classical diffusion in laser-kicked molecular rotors

我们实验研究了一个系统的量子踢转子-一个合奏的双原子分子暴露于一个周期性序列的超短激光脉冲。在该制度下，基本的经典动力学是混沌的，我们调查的量子动力学局域化现象的状态分辨相干拉曼光谱。我们研究的依赖性的指数本地化的角动量分布和总的旋转能量的脉冲和它们的振幅之间的时间周期。前一个参数被示出为提供对定位中心的控制，而后者控制定位长度。类似的控制的中心和宽度的非本地化的旋转分布证明在经典扩散的限制，通过添加噪声的周期性脉冲序列。