论文标题
量子井中非辐射激子水库的非线性行为
Nonlinear behaviour of the nonradiative exciton reservoir in quantum wells
论文作者
论文摘要
带有大波动矢量的激子和自由载体形成非放射性储层，由于激子 - exciton和Ickiton-Carrier相互作用，它们会强烈影响明亮的激子的性质。在目前的工作中，在GAAS/Algaas量子中，使用时间分辨的反射率光谱谱图在GAAS/GAAS量子孔中进行了实验研究，在储层中的准颗粒的动力学进行了实验研究。储层的种群由激发能力或正在研究的结构温度控制。在早先开发的模型的框架中，对动力学进行了定量分析[Kurdyubov等，Phys。修订版B {\ bf 104}，035414（2021）]。该模型考虑了几个动态过程，例如将光激发的激子散射到储层中，将激素分离为自由电荷载体，以及反向过程，载体引起的激子散射在光锥中耗尽了储层，热激活的携带者的非激活携带者的非自传射损失。我们发现，这些过程的竞争会导致储层激子的高度非线性动力学，尽管它们的密度远低于激子莫特过渡密度。确定过程的特征速率及其对激发能力和温度的依赖性。
Excitons and free charge carriers with large wave vectors form a nonradiative reservoir, which can strongly affect properties of bright excitons due to the exciton-exciton and exciton-carrier interactions. In the present work, the dynamics of quasiparticles in the reservoir at different areal densities is experimentally studied in a GaAs/AlGaAs quantum well using a time-resolved reflectance spectroscopy of nonradiative broadening of exciton resonances. The population of the reservoir is controlled either by the excitation power or by the temperature of the structure under study. The dynamics is quantitatively analyzed in the framework of the model developed earlier [Kurdyubov et al., Phys. Rev. B {\bf 104}, 035414 (2021)]. The model considers several dynamic processes, such as scattering of photoexcited excitons into the reservoir, dissociation of excitons into free charge carriers and the reverse process, carrier-induced exciton scattering into the light cone depleting the reservoir, thermally activated nonradiative losses of charge carriers. We have found that competition of these processes leads to highly nonlinear dynamics of reservoir excitons, although their density is far below the exciton Mott transition densities. Characteristic rates of the processes and their dependencies on the excitation power and the temperature are determined.
