Topological Surface States and Anisotropic Magnetotransport in SnSb${}_6$Te${}_{10}$

Abstract

We have investigated the electronic structure and magnetotransport properties of SnSb${}_6$Te${}_{10}$ single crystals using density functional theory (DFT), synchrotron-based angle-resolved photoemission spectroscopy (ARPES), and quantum transport measurements. Our DFT calculations reveal a clear spin-orbit coupling driven band inversion between the Sb-$p$ and Te-$p$ states together with a non-trivial ${\mathbb{Z}}_2$ topological invariant. The calculated surface-state dispersion and hexagonally warped Fermi surface contours agree well with the ARPES measurements. Temperature-dependent transport measurements indicate dominant electron-phonon scattering, while Hall measurements confirm hole-type carriers with carrier density of the order of $10^{21}$ cm${}^{-3}$. Both transverse and longitudinal magnetotransport exhibit weak antilocalization behavior, while Shubnikov-de Haas oscillations observed for $H\parallel c$ yield a Berry phase close to $\ddot{I}€$, consistent with Dirac-like surface states. Furthermore, angle-dependent magnetotransport measurements reveal pronounced anisotropy associated with an anisotropic Fermi surface topology and mixed bulk-surface transport behavior. Our combined theoretical and experimental results establish SnSb${}_6$Te${}_{10}$ as a strong topological insulator and a promising platform for investigating topological transport phenomena in layered telluride systems.

10 pages, 7 figures