Rydberg excitons in the many-particle system solid

首次在氧化亚铜中观测到主要量子数为n&gt；20的激子，开启了半导体物理学一个新的快速发展的研究领域：里德堡激子物理学。里德堡阻塞的观测起到了重要作用。在里德堡阻塞中，激子的存在阻止了由于偶极-偶极相互作用而产生的进一步激子的激发，这在里德堡原子的物理学中是众所周知的。在解释迄今所获得的实验结果方面，成功地依赖于原子概念的应用。然而，如果周围固态的影响变得占主导地位并不得不修改，这些概念就会失效。周围介质的这种影响例如与声子、光子、杂质或缺陷的相互作用，特别是与电子-空穴等离子体的相互作用。从第一个结果可以预料到对里德堡激子的强烈影响，例如，表现为随着等离子体密度的增加(等离子体阻塞)，吸收线的强度系统性地降低。在氧化亚铜中，由于两个激子衰变成电子-空穴对的俄歇效应，激子的任何光激发都不可避免地导致电子-空穴等离子体的存在，从而产生额外的阻塞效应。该项目的中心目标是等离子体效应的多粒子理论基础，阻塞机制的研究，以及等离子体弛豫动力学的实验澄清。

The first observation of excitons with main quantum numbers of n>20 in cuprous oxide has initiated a new and rapidly growing research area of semiconductor physics: the physics of Rydberg excitons. The observation of the Rydberg blockade, where the presence of an exciton prevents the excitation of further excitons due to dipole-dipole interactions, well-known in the physics of Rydberg atoms, has played an important role.The success in the interpretation of the experimental results obtained so far has relied on the application of atomic concepts. However, these concepts fail if the influence of the surrounding solid state becomes dominant and have to be modified.Such influences of the surrounding medium are, e.g., the interactions with phonons, photons, impurities or defects, and, in particular, with an electron-hole plasma. From first results one can expect a strong influence on the Rydberg excitons which, e.g., manifests itself in a systematic decrease of the strength of the absorption lines with increasing plasma density (plasma blockade). Due to the Auger effect where two excitons decay into an electron-hole pair, in cuprous oxide, any optical excitation of excitons unavoidably leads to the presence of an electron-hole plasma giving rise to additional blockade effects.The central goals of the project are the many-particle theoretical foundation of the plasma effect, the investigation of the blockade mechanisms, and the experimental clarification of the plasma relaxation dynamics.