Nonvolatile spin field effect transistor based on VSi2N4/Sc2CO2 multiferroic heterostructure

In this study, we present first-principles calculations that introduce a nonvolatile spin field effect transistor (spin-FET) utilizing a van der Waals multiferroic heterostructure, specifically ${\mathrm{VSi}}_{2}{\mathrm{N}}_{4}/{\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$. We demonstrate that inverting the ferroelectric polarization in a ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$ monolayer can effectively modulate the electronic states of a ${\mathrm{VSi}}_{2}{\mathrm{N}}_{4}$ monolayer, enabling a transition from half-metal to half-semiconductor. This transition significantly alters the electronic transport properties. Furthermore, we construct a spin-FET device based on this multiferroic heterostructure and observe that the ${\mathrm{VSi}}_{2}{\mathrm{N}}_{4}/{\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$-based spin-FET exhibits exceptional all-electric-controlled performance. Notably, the inversion of the ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$ ferroelectric polarization yields a substantial on-off current ratio, approximately 650%, under a minimal bias voltage of 0.02 V. Additionally, we identify a unique spatially separated spin-polarized transport phenomenon, wherein pure spin-up electrons transport exclusively through ${\mathrm{VSi}}_{2}{\mathrm{N}}_{4}$, and spin-down electrons through ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$. Our findings suggest a promising pathway for developing low-energy dissipation and nonvolatile FET devices.