Experimental evidence for topological surface states wrapping around bulk SnTe crystal

TL;DR

This study provides experimental evidence that topological surface states in SnTe wrap around the entire bulk crystal, confirmed through quantum oscillation measurements and theoretical modeling, highlighting their universal topological nature.

Contribution

The paper demonstrates that topological surface states in SnTe surround the bulk crystal on all sides, confirmed by combined experimental and theoretical analysis of quantum oscillations.

Findings

Surface states wrap around all sides of SnTe crystal.

Surface states exhibit a -Berry phase confirming Dirac fermions.

Bulk and surface Landau states coexist in parallel.

Abstract

We demonstrate that the metallic topological surface states wrap on all sides the 3D topological crystalline insulator SnTe. This is achieved by studying oscillatory quantum magneto-transport and magnetization at tilted magnetic fields which enables us to observe simultaneous contributions from neighbouring sample sides. Taking into account pinning of the Fermi energy by the SnTe reservoir we successfully describe theoretically the de Haas-van Alphen oscillations of magnetization. The determined \pi-Berry phase of surface states confirms their Dirac fermion character. We independently observe oscillatory contributions of magneto-transport and magnetization originating from the bulk SnTe reservoir of high hole density. It is concluded that the bulk and surface Landau states exist in parallel. Our main result that the bulk reservoir is surrounded on all sides by the topological surface states has an universal character.