原子-硅藻反应碰撞中的规则和混沌量子动力学

Wigner distribution and Boltzmann-Shannon entropy for a diatomic molecule under polarized electric field interaction

We study the classical chaos appearing in a diatomic molecules $BeO$, $CO$ and $CN$ due to the interaction with a circularly polarized electric field, and its signature in Quantum Mechanics through the Wigner distribution function and the Boltzmann-Shannon entropy. We found a motion out of the center of the quantum phase space defined by Wigner function when the classical system becomes chaotic, and we found a jumping behavior of the average Boltzmann-Shannon entropy with respect the electric field strength when the classical system becomes chaotic, indicating a sudden increasing in the disord…

Chaotic evolution of the energy of the electron orbital and the hopping integral in diatomic molecule cations subjected to harmonic excitation

We analysed the dynamics of the positively charged ions of diatomic molecules (${\rm X_{2}^{+}}$ and ${\rm XY^{+}}$), in which the bond is realised by the single electron. We assumed that the atomic cores separated by the distance $R$ were subjected to the external excitation of the harmonic type with the amplitude $A$ and frequency $Ω$. We found the ground states of ions using the variational approach within the formalism of second quantization (the Wannier function was reproduced by means of Gaussian orbitals). It occurred that, on the account of the highly non-linear dependence of the total…

Experimental demonstration of coherent control in quantum chaotic systems

We experimentally demonstrate coherent control of a quantum system, whose dynamics is chaotic in the classical limit. Interaction of diatomic molecules with a periodic sequence of ultrashort laser pulses leads to the dynamical localization of the molecular angular momentum, a characteristic feature of the chaotic quantum kicked rotor. By changing the phases of the rotational states in the initially prepared coherent wave packet, we control the rotational distribution of the final localized state and its total energy. We demonstrate the anticipated sensitivity of control to the exact parameters…

Quantum Reactive Scattering of Ultracold Atoms and Molecules: Universality and Chaotic Dynamics

A fundamental question in the study of chemical reactions is how reactions proceed at a collision energy close to absolute zero. This question is no longer hypothetical: quantum degenerate gases of atoms and molecules can now be created at temperatures lower than a few tens of nanoKelvin. In this work we consider the benchmark ultracold reaction between, the most-celebrated ultracold molecule, KRb and K. For the first time we map out an accurate ab initio ground state potential energy surface of the KRbK complex in full dimensionality and report numerically exact quantum-mechanical reaction dy…

重新审视芝诺悖论：原子-硅藻反应的飞箭

Revisiting Zeno's paradox: Flying arrows for atom-diatom reactions

利用含时波包传播方法，研究了两种不同过程（F+HD和H+O_2）中原子-硅藻反应碰撞的量子Zeno和反Zeno情形的可能性.提出了一种新的方法，在该方法中，生存概率的调查是那些获得的初始状态被重新定义后的时间间隔τ在该系统上进行测量。与未扰动系统的实际概率的比较揭示了存在一种制度，其中从初始状态的衰减似乎被抑制（量子芝诺效应）或加速（反芝诺效应）。与前面的解释相反，假定时间演化的波包在任何时候都不受影响（“飞箭”），本过程不需要调用违反直觉的受阻演化（“停止箭头”）来解释结果。相反，系统参考态的连续更新解决了明显的现代版本的芝诺悖论。

混沌和规则浴动力学中退相干率的温度交叉

Temperature crossover of decoherence rates in chaotic and regular bath dynamics

研究了在恒温碰撞浴中双原子分子振动自由度的混沌浴动力学对量子系统退相干的影响。作为一个例子，在液体氙中的I $_2$的具体情况下，作为温度的函数进行检查，并与可积氙浴的结果进行比较。一个交叉的行为被发现：可积浴诱导更多的退相干在低浴温度比混乱浴，而相反的情况下，在较高的浴温度。这些结果验证了Wilkie的一个猜想，阐明了混沌动力学对系统退相干影响的不同观点。