Subradiance and Matter Licht-Entanglement with Bose Einstein Condensates in Optical Ring Resonators

冷原子和高精细光学谐振腔的结合为研究原子光相互作用的基本方面提供了一个近乎理想的模型系统。在本项目中，将开发一种线宽低于Rb D2谱线的单光子反冲位移的环形谐振器。利用这样的反冲分辨谐振腔，将产生并研究集体亚辐射态。作为第二个主题，我们将在不同的泵浦场景下研究谐振器诱导的原子与光之间的纠缠。为此，将开发一种单原子探测器，它允许观察亚辐射态的(2)g关联函数。该探测器还将被用来研究卡尔阈值附近的量子涨落：在临界泵浦强度以上，光子散射突然增加，而原子沿着泵浦光束方向被强烈加速。在这个阈值附近，预测了原子与光的纠缠，这导致了非经典的互相关函数。特别是，应该回答的问题是，阈值可以解释为量子相变到什么程度。

The combination of cold atoms and high finesse optical resonators offers an almost ideal model system for investigating fundamental aspects of atom light interaction. In the presented project, a ring resonator will be developed with a line width below the single photon recoil shift of the rubidium D2-line. By means of such a recoil resolving resonator, collective subradiant states will be generated and investigated. As second topic, resonator induced entanglement between atoms and light will be studied for various pump scenarios. For this purpose, a single atom detector will be developed which allows for observing the (2)g-correlation functions for subradiant states. The detector will also be used to study the quantum fluctuations near the CARL- threshold: Above a critical pump intensity photon scattering is suddenly increases while the atoms are strongly accelerated along the direction of the pump beam. Near this threshold, atom-light-entanglement is predicted which leads to non-classical cross-correlation functions. In particular, the question should be answered to which extend the threshold can be interpreted as a quantum phase transition.