Split Fermi Surface Properties of VSi2without Mirror Planes in the Chiral Crystal Structure

Abstract

VSi2 is hexagonal in the crystal structure, and the basal plane stacks along the [0001] direction. Interestingly, each plane is rotated by 60\circ relative to the neighboring one. Therefore, there exist no mirror planes in this chiral structure. We carried out a de Haas–van Alphen (dHvA) experiment and clarified the Fermi surface properties. Each dHvA branch was found to be split into two branches on the basis of the antisymmetric spin–orbit interaction. The magnitude of the antisymmetric spin–orbit interaction in this chiral structure was determined for the first time to be 19 K for dHvA branch α (dHvA frequency \(F = 7.9 \times 10^{7}\) Oe and cyclotron mass \(m^{*}_{\text{c}} = 1.6\) \(m_{0}\)), 39 K for branch β (\(F = 4.1 \times 10^{7}\) Oe and \(m^{*}_{\text{c}} = 3.4\) \(m_{0}\)), and 110 K for branch γ (\(F = 1.8 \times 10^{7}\) Oe and \(m^{*}_{\text{c}} = 2.3\) \(m_{0}\)). These dHvA branches correspond to the main Fermi surfaces, which are well explained by the results of the energy band calculations based on the full potential linear augmented plane wave (FLAPW) method. The present values are mainly due to the V-\(3d\) conduction electrons.