On-demand generation of indistinguishable polarization-entangled photon pairs
On-demand generation of indistinguishable polarization-entangled photon pairs
复制标题
DOI：
10.1038/nphoton.2013.377
复制
发表时间：
2014-03-01
期刊：
影响因子：
35
通讯作者：
Michler, P.
中科院分区：
文献类型：
--
作者：
Mueller, M.;Bounouar, S.;Michler, P.
不可区分和纠缠的光子对的按需源是各种量子信息应用的基本组件，包括光量子计算、量子中继器、量子隐形传态和量子通信(1)。纠缠光子的参数下转换(2，3)和四波混频源(4)已经显示出高度的纠缠和不可分辨，但它们产生过程的概率性质也产生了遵循泊松分布的零或多个光子对。这限制了它们在需要许多量子比特和门操作的复杂算法中的使用。在这里，我们同时展示了从单个半导体量子点产生超高纯度(g((2))(0)<；0.004)、高纠缠保真度(0.81+/-0.02)、高双光子干涉非后选择性可见度(0.86+/-0.03和0.71+/-0.04)和按需产生偏振纠缠光子对(效率ε(对)=0.86+/-0.08)。通过双光子共振激发方案，确定地由一个pi脉冲(epsilon(双激子)=0.98+/-0.07)制备双激子布居。应用于没有激子精细结构分裂的量子点，这将导致无法区分的纠缠光子对的确定性产生。
An on-demand source of indistinguishable and entangled photon pairs is a fundamental component of various quantum information applications, including optical quantum computing, quantum repeaters, quantum teleportation and quantum communication(1). Parametric downconversion(2,3) and four-wave mixing sources(4) of entangled photons have shown high degrees of entanglement and indistinguishability, but the probabilistic nature of their generation process also creates zero or multiple photon pairs following a Poissonian distribution. This limits their use in complex algorithms where many qubits and gate operations are required. Here, we simultaneously show ultrahigh purity (g((2))(0) < 0.004), high entanglement fidelity (0.81 +/- 0.02), high two-photon interference non-post selective visibilities (0.86 +/- 0.03 and 0.71 +/- 0.04) and on-demand generation (efficiency epsilon(pair) = 0.86 +/- 0.08) of polarization-entangled photon pairs from a single semiconductor quantum dot. Through a two-photon resonant excitation scheme, the biexciton population is deterministically prepared by a pi-pulse (epsilon(biexciton) = 0.98 +/- 0.07). Applied on a quantum dot showing no exciton fine-structure splitting, this results in the deterministic generation of indistinguishable entangled photon pairs.