Novel magnetic topological insulator FeBi$_2$Te$_4$ with controllable topological quantum phase

TL;DR

This study predicts that the magnetic topological insulator FeBi$_2$Te$_4$ can undergo multiple topological phase transitions under pressure, with potential applications in quantum technologies.

Contribution

We introduce FeBi$_2$Te$_4$ as a new intrinsic magnetic topological insulator with pressure-tunable topological phases based on first-principles calculations.

Findings

FeBi$_2$Te$_4$ is a non-trivial topological insulator without pressure.

Under pressure, it transitions from topological insulator to semimetal and then to trivial insulator.

Topological phase transitions are driven by magnetic moments and spin-orbit coupling.

Abstract

Here, we report a new intrinsic magnetic topological insulator FeBi$_2$Te$_4$ based on first-principles calculations and it can achieve a rich topological phase under pressure modulation. Without pressure, we predict that both FeBi$_2$Te$_4$ ferromagnetic and antiferromagnetic orders are non-trivial topological insulators. Furthermore, FeBi$_2$Te$_4$ of FM-z order will undergo a series of phase transitions from topological insulator to semimetals and then to trivial insulator under pressure. Finally, we further clarify and verify topological phase transitions with low-energy effective model calculations. This topological phase transition process is attributed to the synergy of the magnetic moment and the spin-orbit coupling. The unique topological properties of FeBi$_2$Te$_4$ will be of great interest in driving the development of quantum effects.