The sub-laser-cycle timescale of the electronic response to strong fields enables attosecond dynamical imaging in atoms, molecules and solids^1,2,3,4, with optical tunnelling and high-harmonic generation the hallmarks of attosecond optical spectroscopy^2,5,6,7. Topological insulators are intimately linked with electron dynamics, as manifested via the chiral edge currents⁸, but it is unclear if and how topology leaves its mark on optical tunnelling and sub-cycle electronic response. Here, we identify distinct bulk topological effects on directionality and timing of currents arising during electron injection into conduction bands. We show that electrons tunnel differently in trivial and topological insulators, for the same band structure, and identify the key role of the Berry curvature in this process. These effects map onto topologically dependent attosecond delays and helicities of emitted harmonics that record the phase diagram of the system. Our findings create new roadmaps in studies of topological systems, building on the ubiquitous properties of the sub-laser-cycle strong-field response—a unique mark of attosecond science.

对强场的电子响应的亚激光周期时标可实现原子，分子和固体^{1,2,3,4中的亚}秒动态成像，并具有光隧道效应和高谐波生成，这是阿秒光谱的特征^{2,5， 6,7}。拓扑绝缘体与电子动力学密切相关，如通过手性边缘电流^8所示，但尚不清楚拓扑是否以及如何在光隧道和子周期电子响应中留下它的印记。在这里，我们确定了电子注入导带过程中产生的电流的方向性和时序的明显本体拓扑效应。我们表明，对于相同的能带结构，电子在平凡和拓扑绝缘体中的隧穿方式不同，并确定了贝里曲率在此过程中的关键作用。这些影响映射到拓扑相关的阿秒延迟和发射谐波的螺旋度，这些谐波记录了系统的相图。我们的发现基于亚激光周期强场响应的无处不在的特性（这是阿秒科学的独特标志），在拓扑系统的研究中创建了新的路线图。