Defects Engineering of ZrTe5 for Stabilizing Ideal Topological States

TL;DR

This study systematically investigates intrinsic defects in ZrTe5 to identify methods for stabilizing its ideal topological states, emphasizing defect control during crystal growth to achieve reproducible quantum properties.

Contribution

It provides a comprehensive first-principles analysis of defects in ZrTe5 and proposes defect engineering strategies to stabilize its topological phases.

Findings

Increasing Te/Zr ratio suppresses intrinsic defects.

Defect competition influences Fermi-level positioning.

Optimized defect control stabilizes weak topological insulator state.

Abstract

ZrTe5 is a highly tunable, high-mobility topological material that hosts a rich variety of quantum phenomena, making it a promising platform for next-generation quantum technologies. Despite intensive research efforts, experimental studies have reported inconsistent and sometimes conflicting results for its electronic and topological states, largely due to variations in sample quality. Here, through systematic frst-principles investigations of all intrinsic point defects, we identify a practical route to achieving stable and ideal topological characteristics in ZrTe5. We show that the competition between two dominant charged defects, donor-like Zr interstitials and acceptor-like Te vacancies, governs the Fermi-level position. Furthermore, variations in defect density determine the topological phases of the samples. We theoretically propose and experimentally confrm that increasing the Te/Zr ratio during crystal growth effectively suppresses intrinsic defects and stabilizes ZrTe5 in a nearly ideal weak topological insulator state. These fndings provide clear guidance for defect control and sample optimization, paving the way toward robust and reproducible realization of topological quantum states in ZrTe5 for future quantum applications.