Controlling photochemistry via quantum superpositions of electronic states: towards attochemistry

通过电子态的量子叠加控制光化学：走向原子化学

• 批准号: 2601202
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2601202
• 关键词: Controlling; photochemistry; via; quantum; superpositions

In this project we will explore - using computational simulations - how laser manipulation of electronic motion in molecules might offer unprecedented control over photochemistry. The central question we seek to answer is: can we direct the outcome of a photochemical process by controlling the initial evolution of a coherent quantum superposition of electronic states in the vicinity of a crossing between these states? Recently attosecond molecular physics has been investigating the concept of "charge migration" i.e. electronic dynamics initiated by sudden excitation of an electron in a molecule or other extended quantum system. It is now clear that a full interpretation of such phenomena must recognise the quantum nature of both electronic and nuclear parts of the system. Decoherence due to the interplay of the evolving coupled nuclear and electronic quantum states is found to be exceptionally rapid and general, taking place on a timescale of a few tens of femtoseconds in all systems studied to date. Any control of photoexcited quantum state dynamics can therefore only be achieved by using light fields which are applied within this decoherence timescale. A target of particular significance is the control of quantum evolution by ultrafast light fields in the vicinity of conical intersections: crossings of potential energy surfaces where non-adiabatic electronic-nuclear couplings lead to crucial transitions between potential chemical pathways. Control here is ultimately control of chemical outcomes. Computer simulations using state-of-the-art code to solve the coupled nuclear-electronic motion will be used to predict and explain the experiments carried out as part of EP/T006943/1. As well as providing new insight into the fundamental behaviour of molecules, the ultrafast quantum science developed here may lead to future quantum devices where the flow of charge, energy and information within a quantum system can be controlled by ultrafast light fields.

在这个项目中，我们将探索-使用计算机模拟-如何激光操纵分子中的电子运动可能提供前所未有的控制光化学。我们寻求回答的中心问题是：我们能否通过控制这些态交叉附近电子态相干量子叠加的初始演化来指导光化学过程的结果？最近阿秒分子物理学一直在研究“电荷迁移”的概念，即由分子或其他扩展量子系统中的电子突然激发引发的电子动力学。现在很清楚，对这种现象的全面解释必须认识到系统的电子和核部分的量子性质。退相干由于不断发展的耦合核和电子量子态的相互作用被发现是非常迅速和普遍的，发生在几十飞秒的时间尺度上的所有系统研究的日期。因此，光激发量子态动力学的任何控制只能通过使用在该退相干时间尺度内施加的光场来实现。一个特别重要的目标是控制量子演化的超快光场在附近的锥形交叉点：交叉的势能面，非绝热的电子-核耦合导致潜在的化学途径之间的关键转变。这里的控制最终是控制化学结果。使用最先进的代码来解决耦合核电子运动的计算机模拟将用于预测和解释作为EP/T006943/1的一部分进行的实验。除了提供对分子基本行为的新见解外，这里开发的超快量子科学可能会导致未来的量子设备，其中量子系统内的电荷，能量和信息的流动可以由超快光场控制。