Changes of Fermi surface topology due to the rhombohedral distortion in SnTe

Cubic SnTe is known to undergo a rhombohedral structural distortion on cooling. Here, the authors show via measuring quantum oscillations that the distortion has a significant impact on the Fermi surface topology. In the distorted structure, several neighboring oscillation frequencies exist as a result of the rhombohedral symmetry breaking and of the spin-orbit splitting, lifting the band degeneracy. By applying a pressure of 10 kbars, it is found that the oscillation spectrum changes and the distortion is suppressed. This allows the authors to determine the contribution to the Hall effect for each feature of the Fermi surface. Additionally, they find unusual linear magnetoresistance that they attribute to regions of the Fermi surface with high curvature.