Multiferroic van der Waals heterostructure FeCl$_2$/Sc$_2$CO$_2$: Nonvolatile electrically switchable electronic and spintronic properties

Abstract

Multiferroic van der Waals (vdW) heterostrucutres offers an exciting route towards novel nanoelectronics and spintronics device technology. Here we investigate the electronic and transport properties of multiferroic vdW heterostructure composed of ferromagnetic FeCl2 monolayer and ferroelectric Sc2CO2 monolayer using first-principles density functional theory and quantum transport simulations. We show that FeCl2/Sc2CO2 heterostructure can be reversibly switched from semiconducting to half-metallic behavior by electrically modulating the ferroelectric polarization states of Sc2CO2. Intriguingly, the half-metallic phase exhibits a Type-III broken gap band alignment, which can be beneficial for tunnelling field-effect transistor application. We perform a quantum transport simulation, based on a proof-of-concept two-terminal nanodevice, to demonstrate allelectric-controlled valving effects uniquely enabled by the nonvolatile ferroelectric switching of the heterostructure. These findings unravels the potential of FeCl2/Sc2CO2 vdW heterostructures as a building block for designing a next generation of ultimately compact information processing, data storage and spintronics devices.