A comprehensive study of the vortex phases and vortex dynamics is presented for a recently discovered high-temperature superconductor YH6 with TC (onset) of 215 K under pressure of 200 GPa.Thermal activation energy (U0) is derived in the framework of thermally activated flux flow (TAFF) theory. The activation energy yields a power law dependence U0∝ Hα on magnetic field with a possible crossover at a field around 8-10 Tesla. Furthermore, we have depicted the vortex phase transition from vortex-glass to vortex-liquid state according to the vortex-glass theory. Finally, vortex phase diagram is constructed for the first time for superhydrides. Very high estimated values of flux flow barriers U0(H) = 1.5-7*104 K together with high crossover fields makes YH6 a rather outstanding superconductor as compared to most cuprates and iron-based systems. The Ginzburg number for YH6 Gi = 3-7*10−3 indicates that thermal fluctuations are not so strong and cannot broaden superconducting transitions in weak magnetic fields.
@article{arxiv.2305.06546,
title = {Vortex phase dynamics in yttrium superhydride YH$_6$ at megabar pressures},
author = {A. V. Sadakov and V. A. Vlasenko and I. A. Troyan and O. A. Sobolevskiy and D. V. Semenok and Di Zhou and V. M. Pudalov},
journal= {arXiv preprint arXiv:2305.06546},
year = {2023}
}