论文标题
Landau-Zener通过一对高阶特殊点进行过渡
Landau-Zener transitions through a pair of higher order exceptional points
论文作者
论文摘要
具有明确时间依赖性的非热量子系统至关重要。在这种情况下，只有少数模型已经进行了分析研究。在这里，引入了PT-对称的非荷米特$ n $ landau-Zener型问题，并引入了两个特殊点$ n $ th订单。该系统在渐近的繁殖时期是隐性化的，距离特殊点很远，并且在特殊点之间纯粹具有虚构的特征值。得出了完整的Landau-Zener过渡概率，并发现显示出特征性的二项式行为。在绝热限制中，最终人群由二项式系数的比率给出。尽管绝热性崩溃通常与非富裕系统相关，但如何基于绝热分析来理解这种行为。
Non-Hermitian quantum systems with explicit time dependence are of ever-increasing importance. There are only a handful of models that have been analytically studied in this context. Here, a PT-symmetric non-Hermitian $N$-level Landau-Zener type problem with two exceptional points of $N$th order is introduced. The system is Hermitian for asymptotically large times, far away from the exceptional points, and has purely imaginary eigenvalues between the exceptional points. The full Landau-Zener transition probabilities are derived, and found to show a characteristic binomial behaviour. In the adiabatic limit the final populations are given by the ratios of binomial coefficients. It is demonstrated how this behaviour can be understood on the basis of adiabatic analysis, despite the breakdown of adiabaticity that is often associated with non-Hermitian systems.
