Rational design principles of quantum anomalous Hall effect from superlattice-like magnetic topological insulators

TL;DR

This paper uses theoretical analysis and first-principle calculations to establish a phase diagram for magnetic topological insulators, revealing design principles to realize the quantum anomalous Hall effect in superlattice-like structures.

Contribution

It introduces a topological phase diagram for superlattice-like magnetic topological insulators and provides practical design principles for achieving QAHE.

Findings

Different configurations exhibit various topological phases.

Tuning slab thickness and magnetization can induce QAHE.

Superlattice-like structures are promising platforms for QAHE.

Abstract

As one of paradigmatic phenomena in condensed matter physics, the quantum anomalous Hall effect (QAHE) in stoichiometric Chern insulators has drawn great interest for years. By using model Hamiltonian analysis and first-principle calculations, we establish a topological phase diagram and map on it with different two-dimensional configurations, which is taken from the recently-grown magnetic topological insulators MnBi4Te7 and MnBi6Te10 with superlattice-like stacking patterns. These configurations manifest various topological phases, including quantum spin Hall effect with and without time-reversal symmetry, as well as QAHE. We then provide design principles to trigger QAHE by tuning experimentally accessible knobs, such as slab thickness and magnetization. Our work reveals that superlattice-like magnetic topological insulators with tunable exchange interaction serve as an ideal platform to realize the long-sought QAHE in pristine compounds, paving a new avenue within the area of topological materials.