Quantum Hall Effect in Chirality-induced Weyl Semiconductor <i>n</i>-type Tellurene

Very recently a new mechanism of generating Weyl nodes were proposed in chiral crystals with strong spin-orbit coupling, which, in sharp contrast to conventional band-inversion-induced Weyl semimetals, can exist in semiconductor systems. Tellurium (Te) is predicted to have these Weyl nodes located at the edge of the conduction band, originated from its DNA-like chiral chain crystal structure. However Te is naturally p-type doped and its conduction band has rarely been studied through transport measurement. In this work we report the first quantum Hall experiment in ALD doped n-type 2D tellurium (dubbed as tellurene) samples with mobility 6,000 cm²/Vs. The chirality-induced Weyl nodes give rise to radial spin texture, and topologically non-trivial π Berry phase was detected in quantum Hall sequences. Additionally, the doping profile forms a wide quantum well with symmetric-antisymmetric energy states leading to an approximate SU(8) isospin symmetry. Our work expands the spectrum of Weyl matters into semiconductor regime for the first time.