Topological phases constitute an exotic form of matter characterized by non-local properties rather than local order parameters¹. The paradigmatic Haldane model on a hexagonal lattice features such topological phases distinguished by an integer topological invariant known as the first Chern number². Recently, the identification of non-equilibrium signatures of topology in the dynamics of such systems has attracted particular attention^3,4,5,6. Here, we experimentally study the dynamical evolution of the wavefunction using time- and momentum-resolved full state tomography for spin-polarized fermionic atoms in driven optical lattices⁷. We observe the appearance, movement and annihilation of dynamical vortices in momentum space after sudden quenches close to the topological phase transition. These dynamical vortices can be interpreted as dynamical Fisher zeros of the Loschmidt amplitude⁸, which signal a so-called dynamical phase transition^9,10. Our results pave the way to a deeper understanding of the connection between topological phases and non-equilibrium dynamics.

拓扑阶段构成了一种具有异国情调的物质，其特征是具有非局部性质，而不是局部有序参数¹。六边形格子上的范式Haldane模型的特征是这样的拓扑相，其特征在于被称为第一个Chern数²的整数拓扑不变量。最近，在这种系统的动力学拓扑的非平衡特征的识别引起了特别的关注^3,4,5,6。在这里，我们使用时间和动量分辨的全态层析成像技术，对驱动的光学晶格中的自旋极化的费米子原子，进行了波函数的动态演化实验^7。。我们观察到突然的淬火接近拓扑相变后，动量空间中动态涡旋的出现，运动和ni灭。这些动态涡旋可以解释为Loschmidt振幅^8的动态Fisher零，这表示所谓的动态相变^9,10。我们的结果为深入理解拓扑阶段与非平衡动力学之间的联系铺平了道路。