# Observation of multichannel quantum coherent transport and electron-electron interaction in Bi2Te3 single crystal

## TL;DR

This study uncovers multichannel quantum coherent transport and electron-electron interactions in a defect-reduced Bi2Te3 crystal, revealing complex bulk conduction mechanisms and the significance of quintuple layers as transport channels.

## Contribution

It demonstrates the presence of multichannel quantum coherent transport in the bulk of Bi2Te3 and identifies each quintuple layer as a separate transport channel, advancing understanding of topological insulator bulk conduction.

## Key findings

- Identification of three transport regimes: thermal activation, defect conduction, and quantum coherence.
- Observation of multichannel two-dimensional quantum coherent transport in the bulk.
- Detection of two-dimensional electron-electron interactions causing dephasing.

## Abstract

The bulk of topological insulators is relatively unexplored due to excess contribution of conduction from native defects. Here we investigate the bulk conduction in a Bi2Te3 crystal having reduced defect induced conduction. Our results uncover the presence of three transport regimes which are dominated by thermal activation across bulk band gap, defect state charge conduction, and quantum coherent transport. The low temperature conductance and magnetoconductance reveal the presence of multichannel two dimensional quantum coherent transport in the bulk. The number of channels are of the order of quintuple layers, signifying each quintuple layer as a single transport channel. These transport channels exhibit two dimensional electron-electron interaction effect causing electron dephasing whereas the defect state bulk conduction exhibits three dimensional electron-electron interaction effect which vanishes on enhancement in defect induced charge carriers.