Santori Charles, Fattal David, Vucković Jelena, Solomon Glenn S, Yamamoto Yoshihisa
Quantum Entanglement Project, ICORP, JST, E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088, USA.
Nature. 2002 Oct 10;419(6907):594-7. doi: 10.1038/nature01086.
Single-photon sources have recently been demonstrated using a variety of devices, including molecules, mesoscopic quantum wells, colour centres, trapped ions and semiconductor quantum dots. Compared with a Poisson-distributed source of the same intensity, these sources rarely emit two or more photons in the same pulse. Numerous applications for single-photon sources have been proposed in the field of quantum information, but most--including linear-optical quantum computation--also require consecutive photons to have identical wave packets. For a source based on a single quantum emitter, the emitter must therefore be excited in a rapid or deterministic way, and interact little with its surrounding environment. Here we test the indistinguishability of photons emitted by a semiconductor quantum dot in a microcavity through a Hong-Ou-Mandel-type two-photon interference experiment. We find that consecutive photons are largely indistinguishable, with a mean wave-packet overlap as large as 0.81, making this source useful in a variety of experiments in quantum optics and quantum information.
最近，人们利用包括分子、介观量子阱、色心、俘获离子和半导体量子点在内的各种器件演示了单光子源。与具有相同强度的泊松分布源相比，这些源在同一脉冲中很少发射两个或更多光子。量子信息领域已经提出了单光子源的许多应用，但大多数应用——包括线性光学量子计算——也要求连续光子具有相同的波包。因此，对于基于单个量子发射器的源，发射器必须以快速或确定性的方式被激发，并且与周围环境的相互作用很小。在这里，我们通过洪-欧-曼德尔型双光子干涉实验测试了微腔中半导体量子点发射的光子的不可区分性。我们发现连续光子在很大程度上是不可区分的，平均波包重叠高达0.81，这使得该源在量子光学和量子信息的各种实验中很有用。
