Modulation of Crystal and Electronic Structures in Topological Insulators by Rare-Earth Doping

Authors

Zengji Yue, University of WollongongFollow
Weiyao Zhao, University of WollongongFollow
David L. Cortie, University of WollongongFollow
Guangsai Yang, University of WollongongFollow
Zhi Li, University of WollongongFollow
Xiaolin Wang, University of WollongongFollow

Publication Details

Yue, Z, Zhao, W, Cortie, D, Yang, G, Li, Z & Wang, X 2019, ‘Modulation of Crystal and Electronic Structures in Topological Insulators by Rare-Earth Doping’, ACS applied electronic materials, vol. 1, no. 9, pp. 1929–1936.

Abstract

We study magnetotransport in a rare-earth-doped topological insulator, Sm_0.1Sb_1.9Te₃ single crystals, under magnetic fields up to 14 T. It is found that that the crystals exhibit Shubnikov–de Haas (SdH) oscillations in their magnetotransport behavior at low temperatures and high magnetic fields. The SdH oscillations result from the mixed contributions of bulk and surface states. We also investigate the SdH oscillations in different orientations of the magnetic field, which reveal a three-dimensional Fermi surface topology. By fitting the oscillatory resistance with the Lifshitz–Kosevich theory, we draw a Landau-level fan diagram that displays the expected nontrivial phase. In addition, the density functional theory calculations show that Sm doping changes the crystal structure and electronic structure compared with those of pure Sb₂Te₃. This work demonstrates that rare-earth doping is an effective way to manipulate the Fermi surface of topological insulators. Our results hold potential for the realization of exotic topological effects in magnetic topological insulators.

Grant Number

ARC/DE180100314