边界态出现在科学的各个领域，为未来电子或光电设备，以及声学和光子学中的声光传播控制提供了潜在的机会。以前关于光子学中边界态的实验主要在线性状态下进行，但目前的研究重点是将非线性效应引入到边界态物理学中，进而形成边缘孤子，光学隔离，使得在这种状态下稳定发射激光。这里，研究人员通过原子相干效应和三光干涉技术在热原子介质中诱导出光子石墨烯，而后在重构光子石墨烯晶格中锯齿形边缘处发现了边界态孤子。为了获得边界态孤子，还引入拉曼增益来抵消边界态光波传播过程中的损耗。该研究结果可能会为未来探索非线性拓扑光子学开辟了道路。
 
Figure 1. 原子能级，线性带隙结构和边界态。                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
 
Figure 2. 实验证实了锯齿形边缘处的边界态。
 

Figure 3. 边缘准孤子的数值模拟实验。

 
Figure 4. 非线性边界态的聚焦，散焦和无衍射传播。
 

Figure 5. 拉曼增益存在下形成边界态孤子。
 
     该研究工作由西安交通大学张彦鹏教授团队联合俄罗斯科学院的Yaroslav V. Kartashov教授于2020年发表在Nature Communications国际权威期刊上。原文：Observation of edge solitons in photonic graphene