The heavy fermion metamagnet uranium ditelluride possesses two distinct magnetic field--induced superconducting states. One of these superconductive phases resides at magnetic fields immediately below a first-order metamagnetic transition to a field--polarized paramagnetic state at a field strength Hm, while the other exists predominantly above Hm. However, little is known about the microscopic properties of this polarized paramagnetic state. Here we report pulsed magnetic field measurements tracking the evolution of Hm for polar and azimuthal inclinations in the vicinity of the crystallographic b−a plane. We uncover a region of the phase diagram at high fields > 50 T with a ripple-like non-monotonic dependence of Hm on the orientation of field. Within this ripple in the metamagnetic transition surface, Hm exhibits an anomalous temperature dependence. Our results point towards the presence of complex magnetic interactions and possible magnetic sub-phases at high magnetic fields in UTe2, which may have important implications for the manifestation of exotic field-induced superconductivity.
@article{arxiv.2503.11362,
title = {Metamagnetic ripples in the UTe2 high magnetic field phase diagram},
author = {Zheyu Wu and Hanyi Chen and Mengmeng Long and Gangjian Jin and Huakun Zuo and Daniel Shaffer and Dmitry V. Chichinadze and Andrej Cabala and Vladimir Sechovsky and Michal Valiska and Zengwei Zhu and Gilbert G. Lonzarich and F. Malte Grosche and Alexander G. Eaton},
journal= {arXiv preprint arXiv:2503.11362},
year = {2025}
}