发表机构
Johannes Kepler University; TU Dortmund University（约翰·开普勒大学; 多特蒙德工业大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对光子量子技术需求，探究低噪声GaAs量子点单光子源的温度特性，通过实验与理论分析揭示高温下光子不可区分度下降的机制，利用腔增强技术在32 K下将其提升至0.80(3)，创该温度下最高报道值。
AI 中文摘要
对于光子量子技术应用而言，能够发射出不可区分度接近1的光子的光源是必不可少的。理想情况下，这些光源不应需要苛刻的制冷系统。本文中，我们对低噪声GaAs量子点中负三激子辐射衰变产生的光子开展了与温度相关的双光子干涉测量，测量结果与考虑载流子-声子相互作用及与激发态耦合的理论计算定量吻合。在最低的探测温度下，发射线宽仅比傅里叶极限高6(2)%，后续发射光子间的不可区分度I达到0.966(6)；而在55 K时，该不可区分度降至0.05(4)。我们表明，这种损失可由与能量接近的激发三激子态的耦合来解释，并提出可通过采用发射速率的珀塞尔增强或增大激发态的能量间隔来提高高温下的光子不可区分度。利用腔增强发射，我们实验验证了第一种途径，在32 K下实现了光子不可区分度从0.314(25)提升至0.80(3)，据我们所知，这是该温度下报道的最高值。
英文摘要
For photonic quantum technology applications, sources capable of emitting photons with indistinguishability close to unity are essential. Ideally, these sources should not require demanding cooling systems. Here, we present temperature-dependent two-photon-interference measurements on photons produced by the radiative decay of the negative trion in a low-noise GaAs quantum dot, which are in quantitative agreement with theoretical calculations accounting for carrier-phonon interactions and coupling to excited states. While at at the lowest explored temperatures the emission linewidth reaches values only 6(2) % above the Fourier limit and the indistinguishability I between subsequently emitted photons reaches 0.966(6), the latter drops to 0.05(4) at 55 K. We show that this loss can be explained with the coupling with energetically close excited trion states and suggest that the photon indistinguishability at elevated temperatures can be increased by employing Purcell enhancement of the emission rate or by increasing the energy separation of the excited states. Using cavity-enhanced emission, we experimentally verify the first route and demonstrate an improvement in photon indistinguishability from 0.314(25) to 0.80(3) at 32 K, which - to our knowledge - is the highest reported value at such temperature.
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