Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography.
Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography.
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DOI：
10.1038/ncomms8662
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发表时间：
2015-07-16
影响因子：
16.6
通讯作者：
Reitzenstein S
中科院分区：
文献类型：
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作者：
Gschrey M;Thoma A;Schnauber P;Seifried M;Schmidt R;Wohlfeil B;Krüger L;Schulze JH;Heindel T;Burger S;Schmidt F;Strittmatter A;Rodt S;Reitzenstein S
先进量子通信的成功关键依赖于非经典光源以高通量率和纯度发射单个不可区分的光子。我们报告确定性制造的微透镜内的单量子点，满足这些要求，在一个灵活和强大的量子器件的方法。在我们的概念中，我们结合联合收割机阴极发光光谱与先进的原位三维电子束光刻在低温下的图案单片微透镜精确地对准预先选定的单量子点以上的分布式布拉格反射器。结果表明，确定性量子点微透镜将光子提取效率提高到（23±3）%。此外，我们还证明了这种微透镜可以保证接近纯的触发单光子发射，并且在饱和时具有高达（80±7）%的光子不可逆性。作为一个独特的特征，单光子纯度和光子不变性在高激发功率和脉冲激发下，甚至在量子发射体的饱和度以上都得到了保持。量子通信需要高通量、高纯度的不可分辨单光子源。在这里，Gschrey等人使用三维电子束光刻来图案化确定性的量子点微透镜，并证明了增强的光子提取效率和光子不可逆性。
The success of advanced quantum communication relies crucially on non-classical light sources emitting single indistinguishable photons at high flux rates and purity. We report on deterministically fabricated microlenses with single quantum dots inside which fulfil these requirements in a flexible and robust quantum device approach. In our concept we combine cathodoluminescence spectroscopy with advanced in situ three-dimensional electron-beam lithography at cryogenic temperatures to pattern monolithic microlenses precisely aligned to pre-selected single quantum dots above a distributed Bragg reflector. We demonstrate that the resulting deterministic quantum-dot microlenses enhance the photon-extraction efficiency to (23±3)%. Furthermore we prove that such microlenses assure close to pure emission of triggered single photons with a high degree of photon indistinguishability up to (80±7)% at saturation. As a unique feature, both single-photon purity and photon indistinguishability are preserved at high excitation power and pulsed excitation, even above saturation of the quantum emitter. Single indistinguishable photon sources with high flux rates and purity are needed in quantum communications. Here, Gschrey et al. use three-dimensional electron-beam lithography to pattern deterministic quantum-dot microlenses and demonstrate enhanced photon-extraction efficiency and photon indistinguishability.