Toshiba Research Europe Limited, Cambridge Research Laboratory, 208 Science Park, Milton Road, Cambridge CB4 0GZ, UK.
Engineering Department, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, UK.
Nat Nanotechnol. 2016 Oct;11(10):857-860. doi: 10.1038/nnano.2016.113. Epub 2016 Jul 18.
Obtaining substantial nonlinear effects at the single-photon level is a considerable challenge that holds great potential for quantum optical measurements and information processing. Of the progress that has been made in recent years one of the most promising methods is to scatter coherent light from quantum emitters, imprinting quantum correlations onto the photons. We report effective interactions between photons, controlled by a single semiconductor quantum dot that is weakly coupled to a monolithic cavity. We show that the nonlinearity of a transition modifies the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and to create polarization-correlated photons from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.
在单光子水平上获得显著的非线性效应是一项重大挑战，这对量子光学测量和信息处理具有巨大的潜力。在近年来取得的进展中，最有前途的方法之一是从量子发射器中散射相干光，将量子相关性刻入光子中。我们报告了一种有效的光子相互作用，它由一个弱耦合到单块腔的单个半导体量子点控制。我们表明，跃迁的非线性会改变泊松光束的计数统计，从而对光子进行数量排序。这用于在检测事件之间创建强相关性，并使用单个自旋从非相关流中创建偏振相关的光子。这些结果为单量子光操作的半导体光开关铺平了道路。
