Disorder masks much of the rich physics in two-dimensional electronic systems, with charged impurities often the limiting factor. In graphene, progress in reducing disorder has largely stagnated since boron nitride encapsulation was introduced a decade ago. Here we show that a brief deep-UV exposure enhances the electronic quality of encapsulated graphene - typically by two orders of magnitude - by neutralizing charged impurities within boron nitride. Following illumination, standard graphene devices exhibit numerous evendenominator fractional quantum Hall states, including non-Abelian candidates, and frequently reveal hidden superlattice minibands. Even macroscopically inhomogeneous devices, seemingly unusable for transport studies, recover after deep-UV illumination and display Landau quantization in millitesla fields. This finding provides a straightforward route to exceptional-quality graphene, enabling further exploration of interaction-driven, topological and other quantum phenomena.
@article{arxiv.2603.29891,
title = {Deep-UV bleaching of charge disorder in encapsulated graphene},
author = {Daniil Domaretskiy and Ned Hayward and Van Huy Nguyen and Simone Benaglia and Kornelia Indykiewicz and Hadrien Vignaud and Jing Zhang and Kenji Watanabe and Takashi Taniguchi and V. I. Fal'ko and Laura Fumagalli and L. A. Ponomarenko and I. V. Grigorieva and A. K. Geim},
journal= {arXiv preprint arXiv:2603.29891},
year = {2026}
}