FIB synthesis of Bi2Se3 1D nanowires demonstrating the co-existence of Shubnikov-de Haas oscillations and linear magnetoresistance

TL;DR

This study uses FIB synthesis to create Bi2Se3 nanowires, demonstrating the coexistence of Shubnikov-de Haas oscillations and linear magnetoresistance, thus confirming the robustness of topological surface states in nanostructures.

Contribution

It introduces a simple FIB milling method to synthesize Bi2Se3 nanowires and systematically investigates their quantum transport properties, highlighting the robustness of topological surface states.

Findings

Coexistence of Shubnikov-de Haas oscillations and linear magnetoresistance observed.

Robustness of topological surface states confirmed despite fabrication process.

Transport properties indicate Dirac dispersive surface states.

Abstract

Since the discovery of topological insulators (TI), there are considerable interests in demonstrating metallic surface states, their shielded robust nature to the backscattering and study their properties at nanoscale dimensions by fabricating nanodevices. Here we address an important scientific issue related to TI whether one can clearly demonstrate the robustness of topological surface states (TSS) to the presence of disorder that does not break any fundamental symmetry. The simple straightforward method of FIB milling was used to synthesize nanowires of Bi2Se3 which we believe an interesting route to test robustness of TSS and obtained results are new compared to many of the earlier papers on quantum transport in TI demonstrating robustness of metallic SS to gallium doping. In presence of perpendicular magnetic field, we have observed the co-existence of Shubnikov de Haas oscillations and linear magnetoresistance which was systematically investigated at different channel lengths indicating the Dirac dispersive surface states. The transport properties and estimated physical parameters shown here demonstrate the robustness of SS to the fabrication tools triggering flexibility to explore new exotic quantum phenomena at nanodevice level.