Quantum Dynamics and Quantum Chaos

本项目将使用纸上笔理论和计算方法来研究分子系统中的量子混沌效应。如果微小的初始变化随着时间呈指数增长，那么系统就被称为混沌系统。归根结底，没有一个量子系统是混沌的(由于测不准原理)，但在实践中，当动力学可以近似经典地处理时，许多系统在短时间内表现出混沌行为。这个项目将建立在阿尔索普小组最近的发现基础上，在这个小组中，早期的量子混沌被证明是由被称为瞬子的离域量子物体控制的。该项目将把这项先前的工作从简单的原型扩展到处理现实的多维模型，包括气体和凝聚相中的振动分子，其中量子混沌的影响尚不清楚，可能会影响对非线性光谱实验的解释。

This project will use pen-on-paper theory and computational methodology to investigate quantum chaotic effects in molecular systems. A system is said to be chaotic if tiny initial changes grow exponentially with time. Ultimately, no quantum system can be chaotic (owing to the uncertainty principle), but in practice many systems behave chaotically at short times when the dynamics can be treated approximately classically. This project will build on recent findings in the Althorpe group in which early-time quantum chaos is shown to be controlled by delocalised quantum objects known as instantons. The project will extend this previous work from simple prototypes to treat realistic multidimensional models, including vibrating molecules in the gas and condensed phase, where the effects of quantum chaos are still unknown and can potentially impact the interpretation of non-linear spectroscopy experiments.