发表机构
Leibniz Universität Hannover; University of Innsbruck; Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences（汉诺威莱布尼茨大学; 因斯布鲁克大学; 奥地利科学院量子光学与量子信息研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究证明无序弱耦合二能级发射体透射光可在连续波弗朗松型测量中违背贝尔不等式，并通过四阶累积展开计算关联，预测在反聚束和聚束两种区域实现违背。
AI 中文摘要
我们证明，通过弱耦合二能级发射体的无序集合透射的光，在连续波弗朗松型测量中可以违背贝尔不等式。贝尔信号由两个稳态输出场关联决定：等时强度关联 $g^{(2)}(0)$ 和相位敏感双光子相干性 $R$。我们利用多体主方程的四阶累积量展开，计算了无序发射体集合中双向传播的这些量。由此产生的贝尔不等式违背出现在两个不同的区域：一个反聚束区域，其中等时符合被抑制；一个聚束区域，其中光子对保持相位相干。将数值外推到具有代表性的弱单发射体耦合 $\beta=0.01$，预测在原子数 $N\backsimeq75$-$220$ 的反聚束区域以及 $N\backsim250$ 的聚束区域出现违背。
英文摘要
We show that light transmitted through a disordered ensemble of weakly coupled two-level emitters can violate a Bell inequality in a continuous-wave Franson-type measurement. The Bell signal is determined by two steady-state output-field correlations, the equal-time intensity correlation $g^{(2)}(0)$ and the phase-sensitive two-photon coherence $R$. We compute these quantities for bidirectional propagation through disordered emitter ensembles using a fourth-order cumulant expansion of the many-body master equation. The resulting Bell inequality violation appears in two distinct regimes, an antibunched regime where equal-time coincidences are suppressed and a bunched regime where photon pairs remain phase coherent. Extrapolating the numerics to a representative weak single-emitter coupling $β=0.01$ predicts violation in the antibunched regime for atom numbers $N\simeq75$-$220$, and in the bunched regime for $N\gtrsim250$.
Comments8 pages, 3 figures
