Control and Imaging of processes triggered by X-ray pulses in multi-center molecules

阿托科学是21世纪最大的科学挑战之一。飞秒激光脉冲为了解核运动的世界提供了一个真实的相机，而阿秒激光脉冲将给我们对电子动力学的理解带来一场革命。阿秒和亚飞秒是原子和分子完全电离和分裂过程中多电子效应的自然时标。使用超短脉冲对化学键中的电子进行阿秒“引导”是操纵分子结构的一种基本方式。控制小分子中的电子运动将为修饰复杂生物分子的结构铺平道路，从而影响到物理、化学和生物等多个领域。这项拟议工作的总体目标是利用超短和超强激光脉冲的特性来时间分辨和控制多中心分子系统中由强X射线激光脉冲触发的阿秒现象。快速的实验进展使人们迫切需要新的理论工具来解决Attoscience面临的挑战。我带来的主要智力武器是我在新的、非主流的准经典技术方面的专业知识，这些技术比量子力学技术快得多，并允许对物理机制进行重大洞察。这些技术适用于通过长程库仑力的电离过程。我建议提供复杂而高效的技术来解决Attoscience面临的一些最基本的问题。我的目标是：1)探索在强烈和超快的X射线脉冲触发的多中心分子分裂过程中双电子逃逸的关联动力学。2)探索多中心分子中电子相干控制和转移的泵浦-探测方案。3)使用红外激光脉冲作为‘阿秒时钟’，精确地将观察到的最终碎片的光谱特性映射到分子被X射线分解时关联电子逃逸动力学的时间演化。

Attoscience is one of the great scientific challenges of the 21st century. While femtosecond laser pulses provided a candid camera into the world of nuclear motion, attosecond laser pulses will bring a revolution in our understanding of electron dynamics. Attoseconds and sub-femtoseconds are the natural time scale for multi-electron effects during complete ionization and break-up of atoms and molecules. Attosecond ``steering" of electrons in chemical bonds using ultra-short pulses is a fundamental way of manipulatingthe molecular structure. Controlling the electronic motion in small molecules will pave the way for modifyingthe structure of complex biomolecules, thus impacting such diverse fields as physics, chemistry and biology. The overall aim of the proposed work is to harness the properties of ultra-short and ultra-strong laser pulses to time-resolve and control attosecond phenomena triggered by intense X-ray laser pulses in multi-center molecular systems. The rapid experimental advances make urgent the quest for new theoretical tools that will address the challenges facing Attoscience. The main intellectual weapon that I bring is my expertise on novel, non-mainstream quasiclassical techniques that are much faster than quantum-mechanical ones and that allow for significant insights into the physical mechanisms. These techniques are appropriate for ionization processes through long range Coulomb forces. I propose to deliver sophisticated and efficient techniques for tackling some of the most fundamental problems facing Attoscience. My objectives are:1)Explore the correlated dynamics of two-electron escape during the break-up of multi-center molecules triggered by intense and ultra-fast X-ray pulses.2)Explore pump-probe schemes for coherent control and transfer of electrons in multi-center molecules.3)Use infrared laser pulses as an ``attosecond clock" to accurately map the properties of the observed spectra of the final fragments to the temporal evolution of correlated electron escape dynamics during the break-up, by X-rays, of molecules.