标题： 波导耦合纳米腔中的普尔塞尔增强型方向光-物质相互作用 显示英文标题

标题： Purcell-Enhanced, Directional Light-Matter Interaction in a Waveguide-Coupled Nanocavity

摘要： 我们通过将量子点（QDs）嵌入波导耦合的纳米腔中，展示了可电调谐的、自旋依赖的、方向性的单光子耦合。 方向性行为源于当与器件波导耦合时，两个腔模之间的方向依赖性干涉。 小模式体积的腔实现了同时的普尔塞增强 (${10.8\pm0.7}$) 和峰值方向对比度 (${88\pm1\%}$)，超过了当前最先进的波导系统。 我们还提出了一个散射矩阵模型来描述该结构的传输特性，以及一个基于量子轨迹的模型来预测系统的方向性，我们利用该模型解释了在量子点器件中观察到的方向对比度的不对称性。 此外，纳米腔实现了发射器方向对比度的宽范围电调谐。 我们展示了结果，表明将量子点发射线精确地从方向对比度${2\%}$调整到${96\%}$。 综合来看，这些特性使这种腔-波导方法有望作为方向性纳米光子电路的基本构建模块。 显示英文摘要

摘要： We demonstrate electrically tunable, spin-dependent, directional coupling of single photons by embedding quantum dots (QDs) in a waveguide-coupled nanocavity. The directional behavior arises from direction-dependent interference between two cavity modes when coupled to the device waveguides. The small mode volume cavity enables simultaneous Purcell enhancement (${10.8\pm0.7}$) and peak directional contrast (${88\pm1\%}$), exceeding current state-of-the-art waveguide-only systems. We also present a scattering matrix model for the transmission through this structure, alongside a quantum trajectory-based model for predicting the system's directionality, which we use to explain the observed asymmetry in directional contrast seen in QD devices. Furthermore, the nanocavity enables wide-range electrical tuning of the emitter's directional contrast. We present results showing precise tuning of a QD emission line from a directional contrast of ${2\%}$ to ${96\%}$. In combination, these characteristics make this cavity-waveguide approach promising for use as a building block in directional nanophotonic circuits.