The three-dimensional (3D) local atomic structures and crystal defects at the interfaces of heterostructures control their electronic, magnetic, optical, catalytic, and topological quantum properties but have thus far eluded any direct experimental determination. Here, we use atomic electron tomography to determine the 3D local atomic positions at the interface of a MoS₂-WSe₂ heterojunction with picometer precision and correlate 3D atomic defects with localized vibrational properties at the epitaxial interface. We observe point defects, bond distortion, and atomic-scale ripples and measure the full 3D strain tensor at the heterointerface. By using the experimental 3D atomic coordinates as direct input to first-principles calculations, we reveal new phonon modes localized at the interface, which are corroborated by spatially resolved electron energy-loss spectroscopy. We expect that this work will pave the way for correlating structure-property relationships of a wide range of heterostructure interfaces at the single-atom level.

中文翻译：

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在 2D 异质结构界面捕获 3D 原子缺陷和声子定位

异质结构界面处的三维 (3D) 局部原子结构和晶体缺陷控制着它们的电子、磁、光、催化和拓扑量子特性，但迄今为止还没有任何直接的实验确定。_{在这里，我们使用原子电子断层扫描来确定 MoS 2} -WSe ₂界面处的 3D 局部原子位置具有皮米精度的异质结，并将 3D 原子缺陷与外延界面处的局部振动特性相关联。我们观察点缺陷、键变形和原子级波纹，并测量异质界面处的完整 3D 应变张量。通过使用实验性 3D 原子坐标作为第一性原理计算的直接输入，我们揭示了位于界面处的新声子模式，空间分辨电子能量损失光谱证实了这一点。我们预计这项工作将为在单原子水平上关联各种异质结构界面的结构-性质关系铺平道路。