Coupling $N$ identical emitters to the same field mode is a well-established method to enhance light-matter interaction. However, the resulting $\sqrt{N}$ boost of the coupling strength comes at the cost of a “linearized” (effectively semiclassical) dynamics. Here, we instead demonstrate a new approach for enhancing the coupling constant of a single quantum emitter, while retaining the nonlinear character of the light-matter interaction. We consider a single quantum emitter with $N$ nearly degenerate transitions that are collectively coupled to the same field mode. We show that in such conditions an effective Jaynes-Cummings model emerges with a boosted coupling constant of order $\sqrt{N}$. The validity and consequences of our general conclusions are analytically demonstrated for the instructive case $N=2$. We further observe that our system can closely match the spectral line shapes and photon autocorrelation functions typical of Jaynes-Cummings physics, proving that quantum optical nonlinearities are retained. Our findings match up very well with recent broadband plasmonic nanoresonator strong-coupling experiments and will, therefore, facilitate the control and detection of single-photon nonlinearities at ambient conditions.

中文翻译：

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单量子发射器 Dicke 增强

耦合 $N$相同场模式的相同发射器是增强光-物质相互作用的一种行之有效的方法。然而，由此产生的$\sqrt{N}$耦合强度的提升是以“线性化”（实际上是半经典的）动力学为代价的。在这里，我们展示了一种提高单个量子发射器耦合常数的新方法，同时保留了光-物质相互作用的非线性特征。我们考虑单个量子发射器$N$几乎退化的跃迁共同耦合到相同的场模式。我们表明，在这种情况下，一个有效的 Jaynes-Cummings 模型出现，其阶数耦合常数增加$\sqrt{N}$. 我们的一般结论的有效性和后果在有指导意义的案例中得到了分析证明$N=2$. 我们进一步观察到，我们的系统可以与 Jaynes-Cummings 物理学典型的谱线形状和光子自相关函数紧密匹配，证明保留了量子光学非线性。我们的发现与最近的宽带等离子体纳米谐振器强耦合实验非常吻合，因此将有助于在环境条件下控制和检测单光子非线性。