Magnetotransport properties and evidence of topological insulating state in LaSbTe

TL;DR

This study investigates LaSbTe single crystals, revealing large magnetoresistance, anisotropic transport, and evidence of topological surface states, confirming its topological insulating nature through magnetotransport and magnetization measurements.

Contribution

It provides experimental evidence of topological insulating behavior in LaSbTe, including large magnetoresistance and non-trivial surface states, supported by comprehensive magnetotransport and magnetization analysis.

Findings

Large non-saturating magnetoresistance (~5000%) at 5 K and 9 T

Detection of non-trivial surface states confirming topological insulator nature

High carrier mobilities with balanced electron and hole densities

Abstract

In this report, 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 metal-semiconductor crossover and Kohler scaling analysis, we have discussed the possible origin of the temperature and magnetic field dependence of resistivity. At 5 K and 9 T, a large, non-saturating transverse magnetoresistance (MR) $\sim$ 5$\times$10$^{3}$ \% has been obtained. The MR shows considerable anisotropy, when the magnetic field is applied along different crystallographic directions. The non-linear 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 have been deduced, which result in large MR. The Fermi surface properties have been analyzed from de Haas-van Alphen oscillation. From the magnetization measurement, the signature of non-trivial surface state has been detected, which confirms that LaSbTe is a topological insulator, consistent with the earlier first-principles calculations.