A collaborative research team from the Slovak Academy of Sciences has successfully developed a groundbreaking method to control spin currents in graphene using ferroelectric switching. This innovative approach involves coupling graphene with a monolayer of In2Se3 (Indium Selenide), enabling precise manipulation of spin currents via electrical signals.
The findings, published on November 14, 2025, in the journal Materials Futures, indicate that switching the ferroelectric polarization of In2Se3 can reverse the direction of spin currents in graphene. This advancement marks a significant step toward creating energy-efficient, non-volatile, and magnet-free spintronic devices, which could lead to the development of next-generation spin-based logic and memory systems.
Understanding Spintronics and the Role of Graphene
Spintronics has emerged as a pioneering field in nanoelectronics over the past two decades. It seeks to utilize the intrinsic angular momentum, or spin, of electrons for information processing, presenting advantages over conventional charge-based electronics. Spin-based logic and memory systems promise substantial reductions in power consumption and heat generation, alongside faster operational speeds and non-volatile data retention.
Despite significant advancements in materials and device architecture, a central challenge remains: achieving efficient electrical control of spin currents without relying on external magnetic fields. Traditional magnetic manipulation methods can hinder device scalability and efficiency, prompting researchers to explore alternative solutions, particularly within the realm of two-dimensional (2D) materials.
Graphene, known for its exceptional electronic mobility and long spin-relaxation time, presents a prime opportunity for spintronics. Nevertheless, its weak intrinsic spin-orbit coupling limits direct control over spins. To address this limitation, researchers have begun utilizing van der Waals heterostructures—layering graphene with other 2D materials to introduce new functionalities through proximity effects.
Innovative Heterostructures and Key Findings
In this study, the research team introduced a novel heterostructure by coupling graphene with ferroelectric materials. These materials possess spontaneous electric polarization that can be regulated with an applied voltage. When In2Se3 interfaces with graphene, its electric dipole can disrupt inversion symmetry, allowing for potential spin orientation and pure electric switching.
The researchers examined graphene/In2Se3 heterostructures in two configurations: a perfectly aligned (0°) interface and a twisted geometry (17.5°). Their calculations revealed that reversing the ferroelectric polarization of In2Se3 effectively switches the chirality of spin currents in graphene. At a zero-degree twist, the system exhibited a conventional Rashba-Edelstein effect, where an applied charge current produces a transverse spin accumulation aligned with the ferroelectric polarization. Conversely, at a 17.5° twist, the system transitioned to an unconventional Rashba-Edelstein effect, resulting in a near-collinear alignment of spin current with charge flow, driven by the emergence of a radial Rashba field.
This research lays the groundwork for the potential realization of graphene-based spin transistors controlled by ferroelectric switching. The implications are significant, as this technology could lead to low-energy, high-speed spin logic and memory devices.
The study highlights the benefits of integrating two-dimensional ferroelectric materials with graphene to unlock novel spintronic functionalities. Future efforts will focus on experimental validation of these results to further advance the development of electrically controlled, non-volatile spintronic devices that promise enhanced performance and efficiency.
