Multiferroic van der Waals heterostructure FeCl2/Sc2CO2: Nonvolatile electrically switchable electronic and spintronic properties

Multiferroic van der Waals (vdW) heterostrucutres offer an exciting route toward high-performance nanoelectronics and spintronics device technology. Here we investigate the electronic and transport properties of multiferroic vdW heterostructures composed of a ferromagnetic ${\mathrm{FeCl}}_{2}$ monolayer and a ferroelectric ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$ monolayer using first-principles density functional theory and quantum transport simulations. We show that ${\mathrm{FeCl}}_{2}/{\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$ heterostructure can be reversibly switched from semiconducting to half-metallic behavior by electrically modulating the ferroelectric polarization states of ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$. Intriguingly, the half-metallic phase exhibits a type-III broken gap-band alignment, which can be beneficial for tunneling field-effect transistor applications. We perform a quantum transport simulation based on a proof-of-concept two-terminal nanodevice to demonstrate all-electric-controlled valving effects uniquely enabled by the nonvolatile ferroelectric switching of the heterostructure. These findings unravel the potential of ${\mathrm{FeCl}}_{2}/{\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$ vdW heterostructures as a building block for designing the next generation of ultimately compact information processing, data storage, and spintronics devices.