Inui Yoshitaka, Yamamoto Yoshihisa
Physics and Informatics Laboratories, NTT Research Inc., 940 Stewart Dr, Sunnyvale, CA 94085, USA.
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA.
Entropy (Basel). 2021 May 17;23(5):624. doi: 10.3390/e23050624.
We analytically and numerically show that the Hillery-Zubairy's entanglement criterion is satisfied both below and above the threshold of coupled non-degenerate optical parametric oscillators (NOPOs) with strong nonlinear gain saturation and dissipative linear coupling. We investigated two cases: for large pump mode dissipation, below-threshold entanglement is possible only when the parametric interaction has an enough detuning among the signal, idler, and pump photon modes. On the other hand, for a large dissipative coupling, below-threshold entanglement is possible even when there is no detuning in the parametric interaction. In both cases, a non-Gaussian state entanglement criterion is satisfied even at the threshold. Recent progress in nano-photonic devices might make it possible to experimentally demonstrate this phase transition in a coherent XY machine with quantum correlations.
我们通过解析和数值方法表明，在具有强非线性增益饱和和耗散线性耦合的耦合非简并光学参量振荡器（NOPO）阈值上下，希勒里 - 祖巴里纠缠判据均得到满足。我们研究了两种情况：对于大泵浦模式耗散，仅当参量相互作用在信号、闲频和泵浦光子模式之间有足够失谐时，低于阈值的纠缠才有可能。另一方面，对于大的耗散耦合，即使参量相互作用中没有失谐，低于阈值的纠缠也有可能。在这两种情况下，即使在阈值处也满足非高斯态纠缠判据。纳米光子器件的最新进展可能使在具有量子关联的相干XY机器中通过实验证明这种相变成为可能。
