Novel magnetic topological insulator FeBi2Te4 with controllable topological quantum phase

Abstract

Herein, we report a new intrinsic magnetic topological insulator FeBi₂Te₄ based on first-principles calculations and it can achieve a rich topological phase under pressure modulation. Without pressure, we predict that both FeBi₂Te₄ ferromagnetic and antiferromagnetic orders are non-trivial topological insulators. Furthermore, the FM-z order FeBi₂Te₄ undergoes a series of phase transitions from a topological insulator to semimetal and then to a trivial insulator under pressure. Finally, we further clarify and verify topological phase transitions with low-energy effective model calculation. This topological phase transition process is attributed to the synergy of the magnetic moment and the spin–orbit coupling. The unique topological properties of FeBi₂Te₄ will be of great interest in driving the development of quantum effects.