Tunable interaction-induced localization of surface electrons in antidot nanostructured Bi2Te3 thin films

TL;DR

This study demonstrates that antidot nanostructures in Bi2Te3 thin films can tune electron-electron interactions, leading to controllable localization of surface electrons, with implications for topological insulator transport properties.

Contribution

It reveals how antidot density modulates electron-electron interactions and localization effects in topological insulator thin films, a novel approach to controlling surface electron behavior.

Findings

Antidot density decreases the slope of logarithmic conductivity with temperature.

Enhanced electron-electron interaction dominates decoherence mechanisms.

Antidot-induced reduction of dielectric constant influences electron interactions.

Abstract

Recently, a logarithmic decrease of conductivity has been observed in topological insulators at low temperatures, implying a tendency of localization of surface electrons. Here, we report quantum transport experiments on the topological insulator Bi2Te3 thin films with arrayed antidot nanostructures. With increasing density of the antidots, a systematic decrease is observed in the slope of the logarithmic temperature-dependent conductivity curves, indicating the electron-electron interaction can be tuned by the antidots. Meanwhile, the weak anti-localization effect revealed in magnetoconductivity exhibits an enhanced dominance of electron-electron interaction among decoherence mechanisms. The observation can be understood from an antidot-induced reduction of the effective dielectric constant, which controls the interactions between the surface electrons. Our results clarify the indispensable role of the electron-electron interaction in the localization of surface electrons and indicate the localization of surface electrons in an interacting topological insulator.