Magnetotransport and Berry phase Tuning in Gd-doped Bi2Se3 Topological Insulator Single Crystals

TL;DR

This study explores how Gd doping in Bi2Se3 topological insulators influences magnetotransport properties and Berry phase, revealing that doping can effectively tune the Berry phase without inducing magnetic order.

Contribution

It demonstrates that Gd doping can modify the Berry phase in Bi2Se3 topological insulators, providing a new method to control topological properties without magnetic ordering.

Findings

Gd doping maintains nontrivial Berry phase in SdH oscillations.

Gd doping affects Hall mobility, carrier density, and band topology.

No magnetic ordering observed in Gd-doped crystals.

Abstract

The Berry phase is an important concept in solids, correlated to the band topology, axion electrodynamics and potential applications of topological materials. Here, we investigate the magnetotransport and Berry phase of rare earth element Gd doped Bi2Se3 (Gd_Bi2Se3) topological insulator at low temperatures and high magnetic fields. Gd_Bi2Se3 single crystals show Shubnikov-de Haas (SdH) oscillations with nontrivial Berry phase while Bi2Se3 single crystals show zero Berry phase in SdH oscillations. The temperature dependent magnetization curves can be well fitted with the Curie-Weiss law in 3-300 K region, indicating no magnetic ordering in Gd_Bi2Se3 crystals. Moreover, Gd doping has limited influence on the quantum oscillation parameters (e.g., frequency of oscillations, the area of the Fermi surface, effective electron mass, Fermi wave vectors etc.), but has an impact on the Hall mobility, carrier density, and band topology. Our results demonstrate that Gd doping can tune the Berry phase of topological insulators effectively, which may pave a way for the future realization of many predicted exotic transport phenomena of topological origin.