Strongly correlated quantum solids are characterized by an inherently granular electronic fabric, with spatial patterns that can span multiple length scales in proximity to a critical point. Here, we used a resonant magnetic X-ray scattering nanoprobe with sub-100 nm spatial resolution to directly visualize the texture of antiferromagnetic domains in NdNiO3. Surprisingly, our measurements revealed a highly textured magnetic fabric, which is shown to be robust and nonvolatile even after thermal erasure across its ordering (TNeˊel) temperature. The scale-free distribution of antiferromagnetic domains and its non-integral dimensionality point to a hitherto-unobserved magnetic fractal geometry in this system. These scale-invariant textures directly reflect the continuous nature of the magnetic transition and the proximity of this system to a critical point. The present study not only exposes the near-critical behavior in rare earth nickelates but also underscores the potential for novel X-ray scattering nanoprobes to image the multiscale signatures of criticality near a critical point.
@article{arxiv.1910.02072,
title = {Scale-invariant magnetic textures in the strongly correlated oxide NdNiO$_3$},
author = {Jiarui Li and Jonathan Pelliciari and Claudio Mazzoli and Sara Catalano and Forrest Simmons and Jerzy T. Sadowski and Abraham Levitan and Marta Gibert and Erica Carlson and Jean-Marc Triscone and Stuart Wilkins and Riccardo Comin},
journal= {arXiv preprint arXiv:1910.02072},
year = {2019}
}