Concurrent Multifractality and Anomalous Hall Response in the Nodal Line Semimetal Fe$_3$GeTe$_2$ Near Localization
Abstract
Topological states of matter exhibit unique protection against scattering by disorder. Different topological classes exhibit distinct forms and degrees of protection. Here, we investigate the response of the ferromagnetic nodal line semimetal FeGeTe to disorder and electronic interactions. By combining global magneto-transport with atomic-scale scanning tunneling spectroscopy we find a simultaneous onset of diverse phenomena below a common temperature scale of about 15 K: A crossover from metallic to insulating temperature dependence of the longitudinal resistivity, saturation of the anomalous Hall conductivity to its maximal value, formation of a sharp zero-bias dip in the tunneling density of state, and emergence of multi-fractal structure of the electronic wavefunction peaking at the Fermi energy. These concurrent observations reflect the emergence of a novel energy scale possibly related to the opening of a gap in the nodal line band of FeGeTe. Our study provides overarching insight into the role of disorder, electronic interactions and Berry curvature in setting the micro- and macro-scale responses of topological semimetals.
Keywords
Cite
@article{arxiv.2503.04367,
title = {Concurrent Multifractality and Anomalous Hall Response in the Nodal Line Semimetal Fe$_3$GeTe$_2$ Near Localization},
author = {Subramanian Mathimalar and Ambikesh Gupta and Yotam Roet and Stanislaw Galeski and Rafal Wawrzynczak and Mikel Garcia-Diez and Iñigo Robredo and Praveen Vir and Nitesh Kumar and Walter Schnelle and Karin von Arx and Julia Küspert and Qisi Wang and Johan Chang and Yasmine Sassa and Ady Stern and Felix von Oppen and Maia G. Vergniory and Claudia Felser and Johannes Gooth and Nurit Avraham and Haim Beidenkopf},
journal= {arXiv preprint arXiv:2503.04367},
year = {2025}
}