Magnetotransport properties and evidence of a topological insulating state in LaSbTe

Abstract

In this paper, we present the magnetotransport and magnetization properties of LaSbTe single crystals. Magnetic-field-induced turn-on behavior and low-temperature resistivity plateau have been observed. By adopting both a metal-semiconductor crossover and Kohler scaling analysis, we discuss the possible origin of the temperature and magnetic field dependence of resistivity. At 5 K and 9 T, a large, nonsaturating transverse magnetoresistance (MR) ∼5×10³% is been obtained. The MR shows considerable anisotropy when the magnetic field is applied along different crystallographic directions. The nonlinear field dependence of the Hall resistivity confirms the presence of two types of charge carriers. From the semiclassical two-band fitting of Hall conductivity and longitudinal conductivity, very high carrier mobilities and almost equal electron and hole densities are deduced, which result in large MR. The Fermi surface properties are analyzed from de Haas–van Alphen oscillation. From the magnetization measurement, the signature of the nontrivial surface state is detected, which confirms that LaSbTe is a topological insulator, consistent with the earlier first-principles calculations.