Magnetoelectric oxide films for spin manipulation in graphene

Abstract

The challenge of creating a graphene spin field effect transistor (spin‐FET) demands a magnetic gate dielectric material whose magnetization can be switched electrically. We have grown films of Cr2O3 on top of graphite and graphene by pulsed laser deposition that shows this crucial functionality. We demonstrate that the Cr2O3 films are magnetoelectric by poling them in combined electric and magnetic fields and then using magnetic force microscopy to observe spontaneous surface domain structure as a function of poling field. In addition, we show that the electric field created by a conducting AFM tip can be used to write magnetic patterns in the film that demonstrate the kind of continuous magnetoelectric control needed for a prototype spin‐FET. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)

Towards a Strong Spin–Orbit Coupling Magnetoelectric Transistor

“…More conventional ME spin transistors have been proposed previously [16]- [19], but those studies have not emphasized the value of using a narrow channel conductor with strong spin-orbit coupling (SOC) to enhance the on/off ratio. Manipatruni et al [20] proposed a device based on the combination of an ME dielectric layer and an SOC channel.…”

Moving towards the magnetoelectric graphene transistor

“…14,16 Chromia is thus a promising magnetoelectric gate dielectric that has the potential to induce spin polarization in a graphene overlayer due to the proximity effect. 6,7 Given the aforementioned advantages, the grapheneon-Cr 2 O 3 (0001) system could offer a route to a nonvolatile magnetoelectric spin valve or spin FET. 2,3,7,8 In this work, we report a systematic study of interfacial charge transfer in graphene/Cr 2 O 3 (0001) heterostructures.…”

“…6,7 Given the aforementioned advantages, the grapheneon-Cr 2 O 3 (0001) system could offer a route to a nonvolatile magnetoelectric spin valve or spin FET. 2,3,7,8 In this work, we report a systematic study of interfacial charge transfer in graphene/Cr 2 O 3 (0001) heterostructures. Scanning probe microscopy and Raman studies reveal an interfacial charge transfer between these materials and point to p-type doping of the graphene with up to a 150 meV shift in the Fermi level.…”

Local Dielectric Breakdown Path along c‐Axis Planar Boundaries in Cr2O3 Thin Films

“…These pioneering studies were performed on bulk Cr 2 O 3 , but increasing interest is focused on Cr 2 O 3 films, as devices require thin films . Magnetoelectric switching of Cr 2 O 3 thin films is limited by dielectric breakdown .…”