Disorder-induced linear magnetoresistance in Sr-doped Bi2Se3 thin films

TL;DR

This study investigates the magnetoresistance behavior in Sr-doped Bi2Se3 thin films, revealing that linear magnetoresistance at high fields arises from mobility fluctuations caused by Sr dopants, with implications for topological superconductor research.

Contribution

It demonstrates that disorder-induced mobility fluctuations lead to linear magnetoresistance in Sr-doped Bi2Se3 films, supported by Parish-Littlewood model analysis.

Findings

Weak antilocalization dominates at low fields.

Classical MR is suppressed at high doping.

Linear MR is explained by mobility fluctuations.

Abstract

Sr-doped Bi2Se3 thin films was known as a potential candidate of topological superconductor. The magnetoresistance (MR) of SrxBi2Se3 films with various doping concentrations x were found to be dominated by weak antilocalization (WAL) at low magnetic fields, whereas the classical MR, which originally dominated the MR, was almost completely suppressed. In contrast, the MR of all samples has been observed to be dominated by linear magnetoresistance (LMR) at high magnetic fields. The LMR, having the linear dependence on carrier mobility, can be successfully explained by the Parish-Littlewood model. This indicates that LMR originates from mobility fluctuation induced by Sr dopant atoms in doped Bi2Se3 films.