AI 中文总结
研究时空拓扑流，通过实验展示在动态调制光子晶格中沿移动边界传播的时空拓扑边缘态，源于能隙和动量隙拓扑共存，打破时空对称性，具备自愈合能力，实现从固定态到稳健波传输的转变。
AI 中文摘要
拓扑态以其抗微扰的稳健性而闻名。近期进展在时变介质中引入了动量隙（或时间）拓扑，产生了时间拓扑态。然而，现有动量隙拓扑研究大多局限于非传播界面态；其在波传输方面的潜力，特别是在移动边界处，尚未实现。在此，我们通过实验展示了时空拓扑流：在动态调制的时间合成光子晶格中沿移动边界传播的时空拓扑边缘态。这些流源于能隙和动量隙拓扑的共存，打破了空间和时间平移对称性，既不守恒能量也不守恒动量。值得注意的是，在强局部时空障碍物之后，它们通过虚部准能隙和与辐射体通道的运动解耦，重建其波剖面。我们的结果建立了一种自愈合时空非厄米保护形式，表明时间维度可以将拓扑从固定态和孤立事件转变为稳健、定向和自我恢复的波传输。
英文摘要
Topological states are renowned for their robustness against perturbations. Recent advances have further introduced momentum-gap (or time) topology in time-varying media, enabling temporal topological states. However, existing studies for momentum-gap topology are largely confined to non-propagating interface states; their potential for wave transport, especially at moving boundaries, has yet to be realized. Here, we experimentally demonstrate topological streams in space-time: space-time topological edge states that propagate along a moving boundary in a dynamically modulated time-synthetic photonic lattice. These streams arise from the coexistence of energy-gap and momentum-gap topologies and break both spatial and temporal translation symmetries, conserving neither energy nor momentum. Remarkably, they reconstruct their wave profiles after strong localized spatiotemporal obstacles, enabled by an imaginary quasienergy gap and kinematic decoupling from radiative bulk channels. Our results establish a form of self-healing spatiotemporal non-Hermitian protection, showing that the temporal dimension can transform topology from pinned states and isolated events into robust, directional and self-restoring wave transport.
