Fermiology and Zeeman splitting of the topological metalβ-Re⁡O2probed by de Haas–van Alphen quantum oscillations under high magnetic fields

Abstract

Recently, β-Re⁡O2 was theoretically proposed to be a candidate for Dirac nodal chain metal with hourglasslike energy-momentum dispersion and got considerable attention. Here, we have grown high-quality β-Re⁡O2 single crystals with a residual-resistivity ratio as large as 428. The magnetoresistance (MR) can reach 7 × 104% measured under 9 T at 2 K. The fitting of MR and Hall data simultaneously by maximum entropy mobility spectrum reveals that there are two electron pockets and two hole pockets in β-Re⁡O2 with comparable carrier concentrations, which leads to the large unsaturated MR in β-Re⁡O2. Furthermore, we characterize the fermiology parameters of β-Re⁡O2 through de Haas–van Alphen (dHvA) effect studies at the high field up to 45.2 T. Aided by the Fermi surface (FS) calculated by first-principles, experimental dHvA analysis also substantiates the coexistence of two electron pockets and two hole pockets at the FS, which is in line with mobility spectrum analysis. Remarkably, the Landau fan diagram analysis for one of the electron pockets verifies the nontrivial Berry phase (≈0.87π) in β-Re⁡O2, suggesting that β-Re⁡O2 may be a topological material. In addition, in the high field (>20 T), we also probed signatures of Zeeman splitting, from which the Landé 𝑔 factors are extracted as ∼0.33–0.43. The detailed fermiology of β-Re⁡O2 provides valuable insights into the physical properties of other topological metals with similar characteristics.