Learning the Fuzzy Phases of Small Photonic Condensates.
Learning the Fuzzy Phases of Small Photonic Condensates.
复制标题
DOI：
10.1103/physrevlett.126.150602
复制
发表时间：
2021-04
影响因子：
8.6
通讯作者：
J. D. Rodrigues;H. Dhar;Benjamin T. Walker;Jason M. Smith;R. Oulton;F. Mintert;R. Nyman
中科院分区：
文献类型：
--
作者：
J. D. Rodrigues;H. Dhar;Benjamin T. Walker;Jason M. Smith;R. Oulton;F. Mintert;R. Nyman
相变是集体行为的最终表现，通常只是多粒子系统的特征。在这里，我们描述了仅由几个光子组成的小型光子凝聚体中集体行为的实验观察。此外，还确定了各种平衡和非平衡状态，包括玻色-爱因斯坦凝聚或类激光发射。然而，较小的光子数和较大的相对波动的存在给识别不同的相和相变带来了很大的困难。我们通过采用无监督学习和模糊聚类算法来系统地构建小型光子凝聚体的模糊相图，从而克服了这一限制。因此，我们的结果证明了即使是小光子集合也具有丰富而复杂的相结构，使它们成为在少数粒子水平上研究平衡和非平衡物理的理想平台。
Phase transitions, being the ultimate manifestation of collective behavior, are typically features of many-particle systems only. Here, we describe the experimental observation of collective behavior in small photonic condensates made up of only a few photons. Moreover, a wide range of both equilibrium and nonequilibrium regimes, including Bose-Einstein condensation or laserlike emission are identified. However, the small photon number and the presence of large relative fluctuations places major difficulties in identifying different phases and phase transitions. We overcome this limitation by employing unsupervised learning and fuzzy clustering algorithms to systematically construct the fuzzy phase diagram of our small photonic condensate. Our results thus demonstrate the rich and complex phase structure of even small collections of photons, making them an ideal platform to investigate equilibrium and nonequilibrium physics at the few particle level.