The transport and thermodynamic properties of β-ReO2 crystallizing in a nonsymmorphic structure were studied using high-quality single crystals. An extremely large magnetoresistance (XMR) reaching 22,000 % in a transverse magnetic field of 10 T at 2 K was observed. However, distinguished from other topological semimetals with low carrier densities that show XMR, β-ReO2 has a high electron carrier density of 1 ×1022 cm−3 as determined by Hall measurements and large Fermi surfaces in the electronic structure. In addition, a small Fermi surface with a small effective mass was evidenced by de Haas-van Alphen oscillation measurements. The previous band structure calculations [S. S. Wang, et al., Nat. Commun. 8, 1844 (2017)] showed that two kinds of loops made of Dirac points of hourglass-shaped dispersions exist and are connected to each other by a point to form a string of alternating loops, called the Dirac loop chain (DLC), which are protected by the multiple glide symmetries. Our first-principles calculations revealed the complex Fermi surfaces with the smallest one corresponding to the observed small Fermi surface, which is just located near the DLC. The XMR of β-ReO2 is attributed to the small Fermi surface and thus is likely caused by the DLC.
@article{arxiv.2105.05526,
title = {Extremely large magnetoresistance in the hourglass Dirac loop chain metal \beta-ReO$_{2}$},
author = {Daigorou Hirai and Takahito Anbai and Shinya Uji and Tamio Oguchi and Zenji Hiroi},
journal= {arXiv preprint arXiv:2105.05526},
year = {2021}
}