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 [Phys. Rev. Lett. 126, 246601 (2021)]. 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.