Ferroelectric switching control of spin current in graphene proximitized by In$_2$Se$_3$

TL;DR

This paper demonstrates how ferroelectric switching in In$_2$Se$_3$ can reversibly control spin currents in graphene, enabling new spintronic device functionalities through electronic structure modulation.

Contribution

It introduces a novel platform combining ferroelectric In$_2$Se$_3$ with graphene to control spin textures via ferroelectric polarization switching, supported by first-principles and tight-binding calculations.

Findings

Ferroelectric polarization switching reverses charge-to-spin conversion sign.

Unconventional radial Rashba field emerges in twisted heterostructures.

Rashba phase can be extracted from conversion efficiency ratios.

Abstract

By utilizing the proximity effect, we introduce a platform that exploits ferroelectric switching to modulate spin currents in graphene proximitized by ferroelectric In$_2$Se$_3$ monolayer. Through first-principles calculations and tight-binding modeling, we studied the electronic structure of graphene/In$_2$Se$_3$ heterostructure for twist angles of 0$^{\circ}$ and 17.5$^{\circ}$, considering both ferroelectric polarizations. We discover that switching the ferroelectric polarization reverses the sign of the charge-to-spin conversion coefficients, acting as a chirality switch of the in-plane spin texture in graphene. For the twisted heterostructure, we observed emergence of unconventional radial Rashba field for one ferroelectric polarization direction. Additionally, we demonstrated that the Rashba phase can be directly extracted from the ratio of conversion efficiency coefficients, providing a straightforward approach to characterize the in-plane spin texture in graphene. All the unique features of the studied graphene/In$_2$Se$_3$ heterostructure can be experimentally detected, offering a promising approach for developing advanced spintronic devices with enhanced performance and efficiency.