Quantum phase transitions driven by sliding in bilayer MnBi2Te4

Abstract

Layered material ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ has bridged the fields of topology, magnetism and two-dimensional (2D) van der Waals materials, and attracted tremendous interest recently. Based on the first-principles calculation, we find that the topological, magnetic and ferroelectric properties of ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ bilayer can be engineered by interlayer sliding. By sliding bilayer ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$, the interlayer exchange interaction can be tuned between ferromagnetic and antiferromagnetic, enabling the transition from ferromagnetic insulators to Chern insulators, and the charge transfer would lead to coexistence with antiferromagnetic and ferroelectric phases. Our work paves a different mechanical way to engineer quantum phases in 2D magnetic materials.