Oppel S, Wiegner R, Agarwal G S, von Zanthier J
Institut für Optik, Information und Photonik, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany and Erlangen Graduate School in Advanced Optical Technologies (SAOT), Universität Erlangen-Nürnberg, 91052 Erlangen, Germany.
Institut für Optik, Information und Photonik, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
Phys Rev Lett. 2014 Dec 31;113(26):263606. doi: 10.1103/PhysRevLett.113.263606. Epub 2014 Dec 30.
Superradiance has been an outstanding problem in quantum optics since Dicke introduced the concept of enhanced directional spontaneous emission by an ensemble of identical two-level atoms. The effect is based on the correlated collective Dicke states which turn out to be highly entangled. Here we show that enhanced directional emission of spontaneous radiation can be produced also with statistically independent incoherent sources, via the measurement of higher-order correlation functions of the emitted radiation. Our analysis is applicable to a wide variety of quantum emitters, like trapped atoms, ions, quantum dots, or nitrogen-vacancy centers, and is also valid for incoherent classical emitters. This is experimentally confirmed with up to eight statistically independent thermal light sources. The arrangement to measure the higher-order correlation functions corresponds to a generalized Hanbury Brown-Twiss setup, demonstrating that the two phenomena, superradiance and the Hanbury Brown-Twiss effect, stem from the same interference phenomenon.
自从迪克引入了由一组相同的二能级原子实现增强定向自发辐射的概念以来，超辐射一直是量子光学中的一个突出问题。这种效应基于相关的集体迪克态，结果证明这些态是高度纠缠的。在这里，我们表明，通过测量发射辐射的高阶关联函数，也可以用统计独立的非相干源产生增强的自发辐射定向发射。我们的分析适用于多种量子发射体，如捕获的原子、离子、量子点或氮空位中心，并且对非相干经典发射体也有效。这已通过多达八个统计独立的热光源进行了实验证实。测量高阶关联函数的装置对应于一个广义的汉伯里·布朗-特威斯装置，表明超辐射和汉伯里·布朗-特威斯效应这两种现象源于相同的干涉现象。
