Defects in atomically thin semiconductors and their moiré heterostructures have emerged as a unique testbed for quantum science. Strong light–matter coupling, large spin–orbit interaction and enhanced Coulomb correlations facilitate a spin–photon interface for future qubit operations and efficient single-photon quantum emitters. Yet, directly observing the relevant interplay of the electronic structure of a single defect with other microscopic elementary excitations on their intrinsic length, time and energy scales remained a long-held dream. Here we directly resolve in space, time and energy how a spin–orbit-split energy level of an isolated selenium vacancy in a moiré-distorted WSe₂ monolayer evolves under the controlled excitation of lattice vibrations, using lightwave scanning tunnelling microscopy and spectroscopy. By locally launching a phonon oscillation and taking ultrafast energy-resolved snapshots of the vacancy’s states faster than the vibration period, we directly measure the impact of electron–phonon coupling in an isolated single-atom defect. The combination of atomic spatial, sub-picosecond temporal and millielectronvolt energy resolution marks a disruptive development towards a comprehensive understanding of complex quantum materials, where the key microscopic elementary interactions can now be disentangled, one by one.

原子薄半导体及其莫尔异质结构的缺陷已成为量子科学的独特测试平台。强光-物质耦合、大自旋-轨道相互作用和增强的库仑相关性有利于未来量子位操作和高效单光子量子发射器的自旋-光子界面。然而，直接观察单个缺陷的电子结构与其他微观基本激发在其固有长度、时间和能量尺度上的相关相互作用仍然是一个长期的梦想。在这里，我们使用光波扫描隧道显微镜和光谱学，在空间、时间和能量上直接解析莫尔扭曲的WSe _{2单层中孤立的硒空位的自旋轨道分裂能级在晶格振动的受控激发下如何演化。}通过局部启动声子振荡并以比振动周期更快的速度拍摄空位状态的超快能量分辨快照，我们直接测量了孤立单原子缺陷中电子-声子耦合的影响。原子空间、亚皮秒时间和毫电子伏能量分辨率的结合标志着对复杂量子材料的全面理解的颠覆性发展，现在可以一一解开关键的微观基本相互作用。