Toward ferromagnetic semimetal ground state with multiple Weyl nodes in van der Waals crystal MnSb4Te7

Abstract

The magnetic topological van der Waals materials family MnBi _2 Te _4 /(Bi _2 Te _3 ) _n have drawn markedly attention due to their novel multiple topological phases in different magnetic configurations. Recently, their close relative, the MnSb _4 Te _7 , was firstly synthesized in experiments (2021 Phys. Rev. Lett. 126 246601). To further explore the emergent properties of MnSb _4 Te _7 , we have systematically investigated the magnetic and topological characters under compressive strain and charge doping using first-principles calculations. We predict that MnSb _4 Te _7 transits from an interlayer antiferromagnetic ground state to a ferromagnetic semimetal ground state with multiple Weyl points when compressive strained along c axis above 8% or charge doping before 0.1 hole/formula concentration. Notable anomalous Hall conductivity is also predicted. Meanwhile, the magnetic easy axis can be reoriented from out-of-plane to in-plane orientation when strain or electron doping is applied. The underlying magnetic exchange mechanism is also analyzed from our calculation results. Our work thus provides a feasible way to realize applications of the highly tunable magnetic-topological nature and a comprehensive theoretical understanding of this magnetic topological material.

Keywords

• first-principles calculations
• magnetic phase transition
• van der Waals materials