The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typicall...The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typically achieved via ionic gating)to shift the vHS to the Fermi level provides a general mechanism for engineering such magnetism,its volatile nature often leads to the collapse of induced states upon gate field removal.Here,a novel scheme is presented for non-volatile magnetic control by utilizing ferroelectric heterostructures to achieve reversible magnetism switching.Using two-dimensional VSiN_(3),a nonmagnetic material with Mexican-hat electronic band dispersions hosting vHSs,as a prototype,it is preliminarily demonstrated that both electron and hole doping can robustly induce magnetism.Further,by interfacing VSiN_(3)with ferroelectric Sc_(2)CO_(2),reversible switching of its magnetic state via polarization-driven heterointerfacial charge transfer is achieved.This mechanism enables a dynamic transition between insulating and half-metallic phases in VSiN_(3),establishing a pathway to design multiferroic tunnel junctions with giant tunneling electroresistance or magnetoresistance.This work bridges non-volatile ferroelectric control with vHS-enhanced magnetism,opening opportunities for energy-efficient and high-performance spintronic devices and non-volatile memory devices.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62174016,12474047,12204202,and 11974355)the Basic Research Program of Jiangsu(Grant No.BK20220679)+1 种基金the Fund for Shanxi“1331Project”the Research Project Supported by Shanxi Scholarship Council of China.
文摘The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typically achieved via ionic gating)to shift the vHS to the Fermi level provides a general mechanism for engineering such magnetism,its volatile nature often leads to the collapse of induced states upon gate field removal.Here,a novel scheme is presented for non-volatile magnetic control by utilizing ferroelectric heterostructures to achieve reversible magnetism switching.Using two-dimensional VSiN_(3),a nonmagnetic material with Mexican-hat electronic band dispersions hosting vHSs,as a prototype,it is preliminarily demonstrated that both electron and hole doping can robustly induce magnetism.Further,by interfacing VSiN_(3)with ferroelectric Sc_(2)CO_(2),reversible switching of its magnetic state via polarization-driven heterointerfacial charge transfer is achieved.This mechanism enables a dynamic transition between insulating and half-metallic phases in VSiN_(3),establishing a pathway to design multiferroic tunnel junctions with giant tunneling electroresistance or magnetoresistance.This work bridges non-volatile ferroelectric control with vHS-enhanced magnetism,opening opportunities for energy-efficient and high-performance spintronic devices and non-volatile memory devices.
