Topological Phase Transitions Driven by Magnetic Phase Transitions in FexBi2Te3 (0 <= x <= 0: 1) Single Crystals

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 behavior around x similar to 0.025, and it further evolves to a topological insulator with valence-bond glassy behavior, which spans over the region from x similar to 0.03 up to x similar to 0.1. This phase diagram is verified by measuring magnetization, magnetotransport, and angle-resolved photoemission spectra with theoretical discussions. DOI: 10.1103/PhysRevLett.110.136601