Topological phase transitions driven by magnetic phase transitions in FexBi2Te3 (0 < x < 0.1) single crystals

TL;DR

This paper presents a phase diagram for FexBi2Te3 single crystals showing how magnetic phase transitions induce topological phase changes, verified through experiments and theoretical analysis.

Contribution

It introduces a comprehensive phase diagram linking magnetic correlations to topological phases in FexBi2Te3, supported by experimental and theoretical evidence.

Findings

Magnetic correlations evolve from ferromagnetic to antiferromagnetic with increasing x.

Topological phase transitions occur around specific doping levels.

Experimental data confirms the proposed phase diagram.

Abstract

We propose a phase diagram for FexBi2Te3 (0 < x < 0.1) single crystals, which belong to a class of magnetically bulk-doped topological insulators. The evolution of magnetic correlations from ferromagnetic- to antiferromagnetic- gives rise to topological phase transitions, where the paramagnetic topological insulator of Bi2Te3 turns into a band insulator with ferromagnetic-cluster glassy behaviours around x ~ 0.025, and it further evolves to a topological insulator with valence-bond glassy behaviours, which spans over the region between x ~ 0.03 up to x ~ 0.1. This phase diagram is verified by measuring magnetization, magnetotransport, and angle-resolved photoemission spectra with theoretical discussions.