Capturing 3D atomic defects and phonon localization at the 2D heterostructure interface
Xuezeng Tian, Xingxu Yan, Georgios Varnavides, Yakun Yuan, Dennis S. Kim, Christopher J. Ciccarino, Polina Anikeeva, Ming-Yang Li, Lain-Jong Li, Prineha Narang, Xiaoqing Pan, Jianwei Miao
Abstract
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.