Hyperbolic metamaterial (HMM) can enhance the radiative recombination rate of a near-field coupled emitter due to its large photonic density of states (PDOS). Thus far, this enhancement has only been demonstrated qualitatively on account of the difficulties to achieve an equal emitter–HMM distance as well as the same polarization for all emitters. Here, we report on the deterministic coupling of epitaxially grown quantum dots (QDs) with HMM, for which a quantitative investigation of the rate enhancement is possible. Advantages of epitaxial QDs over other emitters to investigate HMM coupling include a precise QD–HMM distance, the same polarization direction, and single-exponential decay of photoluminescence. In order to isolate metal-related effects, we have fixed the thickness of the silver (Ag) layer and have varied only that of the germanium (Ge) layer in the HMM to investigate the effect of the PDOS, which depends on the dispersion relation, which in turn depends on the thickness ratio. The recombination rate enhancement, as measured by lifetime reduction, varied from 2.2 to 4.2, depending on the thickness ratio of Ag and Ge in the HMM. These findings match well with simulation results, clearly supporting the role of HMM in the rate enhancement. The coupling of high-quality epitaxial QDs with HMM, demonstrated here for the first time, to the best of our knowledge, may bring about diverse future applications.

中文翻译：

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外延半导体量子点与双曲线超材料的确定性耦合

双曲超材料（HMM）由于其大的光子态密度（PDOS）可以提高近场耦合发射器的辐射复合率。到目前为止，由于难以实现相等的发射器-HMM距离以及所有发射器具有相同的极化，因此仅在质量上证明了这种增强。在这里，我们报告外延生长的量子点（QDs）与HMM的确定性耦合，对此可能进行速率增强的定量研究。外延QD优于其他发射器来研究HMM耦合的优势包括精确的QD–HMM距离，相同的偏振方向以及光致发光的单指数衰减。为了隔离金属相关的影响，我们已经固定了银（Ag）层的厚度，并且仅改变了HMM中的锗（Ge）层的厚度，以研究PDOS的效果，这取决于色散关系，而色散关系又取决于厚度比。通过寿命降低来测量的重组速率增强，在2.2至4.2之间变化，这取决于HMM中Ag和Ge的厚度比。这些发现与仿真结果非常吻合，清楚地支持了HMM在速率增强中的作用。据我们所知，本文首次展示了高质量外延QD与HMM的结合，可能会带来各种各样的未来应用。通过减少寿命来测量的值，从2.2到4.2不等，具体取决于HMM中Ag和Ge的厚度比。这些发现与仿真结果非常吻合，清楚地支持了HMM在速率增强中的作用。据我们所知，本文首次展示了高质量外延QD与HMM的结合，可能会带来各种各样的未来应用。通过减少寿命来测量的值，从2.2到4.2不等，具体取决于HMM中Ag和Ge的厚度比。这些发现与仿真结果非常吻合，清楚地支持了HMM在速率增强中的作用。据我们所知，本文首次展示了高质量外延QD与HMM的结合，可能会带来各种各样的未来应用。