近日，美国西北大学的Roel Tempelaar及其研究团队取得一项新进展。经过不懈努力，他们成功处理非绝热动力学中的几何相位效应。相关研究成果已于2024年3月13日在国际知名学术期刊《物理评论A》上发表。

该研究团队提出了一种消除导数耦合规范自由的方法，从而在存在几何相位效应的情况下实现非绝热动力学。这种方法依赖于基于动态变量函数的参数量子哈密顿量的自底向上构造。这些函数可以与给定非绝热基中对哈密顿量的实值和虚值贡献联系起来。

通过最小化虚函数的变量相关波动，研究人员确定了一组恢复拓扑平凡系统常用的实值规范的非绝热基。然而，这种最小化也限制了拓扑非平凡情况下的规范自由度，为寻找几何相位效应下的规范不变导数耦合开辟了道路。研究人员在针对穿越避交叉区域的核波包的最小开关表面跳变计算中，取得了令人振奋的进展，他们发现了完全规范不变的导数耦合。

附：英文原文

Title: Treating geometric phase effects in nonadiabatic dynamics

Author: Alex Krotz, Roel Tempelaar

Issue&Volume: 2024/03/13

Abstract: We present an approach for eliminating the gauge freedom for derivative couplings, enabling nonadiabatic dynamics in the presence of geometric phase effects. This approach relies on a bottom-up construction of a parametric quantum Hamiltonian in terms of functions of a dynamical variable. These functions can be associated with real- and imaginary-valued contributions to the Hamiltonian in a given diabatic basis. By minimizing variable-dependent fluctuations of the imaginary functions we identify a set of diabatic bases that recover the real-valued gauge commonly used for topologically trivial systems. This minimization, however, also confines the gauge freedom in the topologically nontrivial case, opening a path towards finding gauge-invariant derivative couplings under geometric phase effects. Encouraging results are presented for fewest-switches surface-hopping calculations of a nuclear wave packet traversing an avoided-crossing region, for which fully gauge-invariant derivative couplings are found.

DOI: 10.1103/PhysRevA.109.032210

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.032210