Quantum Dynamics and Quantum Chaos

本计画将使用笔在纸上的理论和计算方法来研究分子系统中的量子混沌效应。如果一个系统的微小初始变化随时间呈指数增长，则该系统被称为混沌系统。最终，没有量子系统可以是混沌的（由于不确定性原理），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。该项目将建立在Althorpe小组最近的发现基础上，其中早期量子混沌被证明是由称为瞬子的离域量子物体控制的。该项目将把以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仍然未知，可能会影响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.