Multiferroic van der Waals heterostructure <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>FeCl</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>Sc</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>CO</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>: Nonvolatile electrically switchable electronic and spintronic properties
Liemao Cao, Xiaohui Deng, Guanghui Zhou, Shi‐Jun Liang, Chuong V. Nguyen, L. K. Ang, Yee Sin Ang
Abstract
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.