Fermi surface of magnetic kagome compound GdV6Sn6 investigated using de Haas van Alphen Oscillations

TL;DR

This study characterizes the Fermi surface and effective masses of charge carriers in the kagome magnet GdV6Sn6 using de Haas van Alphen oscillations and band structure calculations, revealing complex 3D and 2D features and saddle-point contributions.

Contribution

It provides detailed experimental and theoretical insights into the Fermi surface topology and effective masses in GdV6Sn6, highlighting saddle-point features unique to kagome lattices.

Findings

Multiple dHvA frequencies indicating complex Fermi surface topology

Presence of both light and heavy charge carriers with distinct effective masses

Fermi surface pockets exhibit both 3D and 2D characteristics

Abstract

The shape of the Fermi surface, and the cyclotron effective mass of the kagome magnet GdV6Sn6 charge carriers are investigated using de Haas van Alphen (dHvA) oscillations measurements and electronic band structure calculations. The temperature and angle-dependent torque magnetometry measurements revealed at least nine different frequencies ranging from ~10 T up to ~9000 T. These frequencies correspond to extremal areas of the Fermi surface ranging from ~0.2 % up to 50% of the first Brillouin zone, qualitatively consistent with the electronic band structure calculations. The angle dependent dHvA oscillation frequencies indicate that the smaller pockets of the Fermi surface have almost 3D character whereas the bigger pockets of the Fermi surface are mostly two-dimensional. We also find evidence of the presence of light (0.28(1) m0) as well as heavy (2.37(18) m0) charge carriers through the analysis of the temperature dependence of dominant frequencies. The comparison of the observed frequencies with the electronic band structure calculations indicates that the heavy masses correspond to saddle-point-like features of electronic band structure at the M point. The observation of the multiple low frequencies and the calculated contributions from various bands to such low frequencies prevent the estimation of topological nature of bands containing lighter fermions. In conclusion, our work reveals the features of a Fermi surface containing enhanced mass fermions originated from saddle points in the electronic band structure at the M point, which is inherent to kagome lattices.