标题： 莫尔材料中拓扑陈数的光学控制 显示英文标题

标题： Optical control over topological Chern number in moiré materials

摘要： 用光控制量子物质为动态调节其多体特性提供了一条有前途的途径，从带拓扑到超导性。 然而，在稳态下对强关联电子系统实现这种光学控制仍然难以实现。 在这里，我们展示了扭曲MoTe2同质结层中巡游铁磁体的自旋-谷自由度的全光开关。 该系统独特地具有平坦的谷对比陈数带，并在不同的莫里晶格填充情况下表现出一系列强关联相，包括陈绝缘体和铁磁金属。 我们表明，通过共振激发吸引极化子跃迁，可以用圆偏振光动态反转所有这些相的自旋-谷方向。 这些发现不仅构成了零磁场下铁磁自旋态非热开关的第一个直接证据，还展示了对拓扑序参数动态控制的可能性，为全光生成手性边缘模式和拓扑量子电路铺平了道路。 显示英文摘要

摘要： Controlling quantum matter with light offers a promising route to dynamically tune its many-body properties, ranging from band topology to superconductivity. However, achieving such optical control for strongly correlated electron systems in the steady-state has remained elusive. Here, we demonstrate all-optical switching of the spin-valley degree of freedom of itinerant ferromagnets in twisted MoTe2 homobilayers. This system uniquely features flat valley-contrasting Chern bands and exhibits a range of strongly correlated phases at various moir\'e lattice fillings, including Chern insulators and ferromagnetic metals. We show that the spin-valley orientation of all of these phases can be dynamically reversed by resonantly exciting the attractive polaron transition with circularly-polarized light. These findings not only constitute the first direct evidence for non-thermal switching of a ferromagnetic spin state at zero magnetic field, but also demonstrate the possibility of dynamical control over topological order parameter, paving the way for all-optical generation of chiral edge modes and topological quantum circuits.