Geometry-tunable magnetic edge contrast in Bi2Te3 Corbino nanoplates

TL;DR

This study demonstrates a method to create Bi2Te3 nanoplates with tunable magnetic edge contrast, revealing how edge interactions depend on geometry, which advances understanding of topological insulator edge states for electronic applications.

Contribution

Developed a Te-rod-templated growth method for Bi2Te3 nanoplates with Corbino geometry, enabling controlled study of magnetic edge contrast and edge interactions in topological insulators.

Findings

Magnetic contrast observed at both edges using magnetic force microscopy.

Edge contrast increases as the distance between edges decreases.

Edge interactions can be tuned via pore size, affecting magnetic behavior.

Abstract

Two-dimensional topological insulators feature helical edge states that are remarkably resistant to disorder, making them appeal for energy-efficient electronics and quantum information technologies. In this study, we develop a Te-rod-templated solution growth method to create Bi2Te3 nanoplates with a Corbino geometry. The resulting few-quintuple-layer hexagonal plates are single-crystalline and contain well-defined central pores. Using optimized magnetic force microscopy, we observe clear magnetic contrast at both the inner and outer edges. The signal depends strongly on tip height and oscillation amplitude, allowing us to distinguish genuine magnetic responses from electrostatic and topographic effects. By systematically varying the pore size, we find that edge contrast increases as the distance between edges decreases, suggesting stronger coupling between the inner and outer edge channels. These findings establish a geometry-controlled platform for tuning edge-localized magnetic behavior in Bi2Te3 and open a new path to explore edge interactions in two-dimensional topological insulators.