Nanoscale topological polar textures promise new functionalities for ferroelectric memories and logic, yet their three-dimensional structure and mesoscale organization remain experimentally inaccessible. Here we introduce depth-resolved electron diffraction imaging (DREDI), a fast, non-destructive, method that maps polarization with <50 nm lateral and <10 nm depth sensitivity within fraction of a second. Its high acquisition speed enables the first continuous polarization mapping across six orders of magnitude in length scale, from nanometers to millimeters. Using epitaxial BiFeO3 films, DREDI reveals a hidden depth evolution of polar textures: surface 71-degree stripes evolve into subsurface flux-closure vortices that bifurcate into three-fold vertices near the bottom interface. Cross-sectional multi-slice electron ptychography and phase-field modeling confirm these buried configurations and attribute them to strain heterogeneity and ferroelastic twinning in the SrRuO3 electrode. Large-area analysis further shows that vertex-like frustration forms a mesoscale percolating network above a critical length scale of 4 um. DREDI enables real-time, volumetric studies of buried topological textures in ferroic nanomaterials.
@article{arxiv.2604.00483,
title = {Revealing buried ferroelectric topologies by depth-resolved electron diffraction imaging},
author = {Ting-Ran Liu and Koushik Jagadish and Xiangwei Guo and Maya Ramesh and Peter Meisenheimer and Harish Kumarasubramanian and Sajid Husain and Ann V. Ngo and Amir Avishai and Jayakanth Ravichandran and Darrell G. Schlom and Ramamoorthy Ramesh and Yu-Tsun Shao},
journal= {arXiv preprint arXiv:2604.00483},
year = {2026}
}