We show that Rashba spin–orbit coupling (SOC) can generate chaotic behavior of excitons in two-dimensional semiconductor structures. To model this chaos, we study a Kepler system with spin–orbit coupling and numerically obtain a transition to chaos at a sufficiently strong coupling. The chaos emerges since the SOC reduces the number of integrals of motion as compared to the number of degrees of freedom. Dynamically, the dependence of the exciton energy on the spin orientation in the presence of SOC produces an anomalous spin-dependent velocity resulting in chaotic motion. We observe numerically the critical dependence of the dynamics on the initial conditions, where the system can return to and exit a stability domain through very small changes in the initial spin orientation. This chaos can have a strong influence on the lifetime of optically injected carriers in semiconductors and organometallic perovskites. Hence, this effect should be taken into account while designing structures for photovoltaic and optical spintronics applications, where excitons play a significant role.

中文翻译：

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自旋轨道耦合对超薄层激子内部运动的混沌化

我们证明，Rashba自旋轨道耦合（SOC）可以在二维半导体结构中产生激子的混沌行为。为了对这种混沌进行建模，我们研究了具有自旋-轨道耦合的开普勒系统，并在足够强的耦合条件下从数值上获得了向混沌的过渡。由于与自由度相比，SOC减少了运动积分的数量，因此出现了混乱。动态地，在存在SOC的情况下，激子能量对自旋取向的依赖性产生异常的自旋依赖性速度，从而导致混沌运动。我们在数值上观察到动力学对初始条件的关键依赖性，在初始条件下，系统可以通过初始自旋方向上的很小变化返回或退出稳定域。这种混乱可能会严重影响半导体和有机金属钙钛矿中光注入载流子的寿命。因此，在设计激子起重要作用的光伏和光学自旋电子学应用的结构时，应考虑到这种影响。