University of Groningen researchers have measured the presence of electron-spin-dependent nonlinearity in a van der Waals heterostructure spintronic device. The team went on to demonstrate its application for basic analog operations such as essential elements of amplitude modulation and frequency sum (heterodyne detection) on pure spin signals, by exploiting the second-harmonic generation of the spin signal due to nonlinear spin injection.
The researchers also showed that the presence of nonlinearity in the spin signal has an amplifying effect on the energy-dependent conductivity-induced nonlinear spin-to-charge conversion effect. The interaction of the two spin-dependent nonlinear effects in the spin-transport channel leads to a highly efficient modulation of the spin-to-charge conversion effect, which in principle can also be measured without using a ferromagnetic detector. These effects are measured both at room and low temperatures, and are suitable for their applications as nonlinear circuit elements in the fields of advanced spintronics and spin-based neuromorphic computing.
The european Graphene Flagship project has announced 16 newly-funded graphene FLAG-ERA projects. These projects which will become Partnering Projects of the Graphene Flagship – receiving around €11 million in funding overall.
Two of these projects will investigate the promising properties of graphene for spintronics. The SOgraphMEM project will test specific materials for a novel branch of spintronics called spin-orbitronics, while the DIMAG project will fabricate new layered magnetic materials with optimal characteristics for spintronics applications.
Researchers from the Korea Advanced Institute of Science and Technology (KAIST) have developed a new method to apply graphene as an active spintronic component for generating, controlling, and detecting spin current without ferromagnetic electrodes or magnetic fields.
The KAIST researchers observed highly efficient charge-to-spin interconversion via the gate-tunable Rashba-Edelstien effect (REE) in graphene heterostructures. The researchers used graphene stacked on top of a large spin-orbit coupling transition metal dichalcogenide material (2H-TaS2).
Researchers from Spain's ICN2 institute have used numerical simulations to show that spin diffusion length in graphene is independent of grain size. The researchers base their calculations on CVD grown graphene. CVD methods produces high quality materials that are built from several single-crystal sheets separated from one another through grain boundaries.
The research have shown that the grain boundaries do not have any effect on the spin transport. The researchers considered two different mechanisms for spin relaxation - randomization of spins within the grains due to spin-orbit coupling, and scattering in a grain boundary. The main implication of this research is that single-domain graphene may not be a requirement for spintronics applications.
The International Institute of Physics in Brazil recently uploaded this interesting talk by Ahmet Avsar, from the EPFL, who discusses spintronics in 2D materials (such as graphene):
This talk was given as part of the IIP's 2D Materials: From Fundamentals to Spintronics workshop which took place in early October.
Researchers from the University of Groningen developed a two-dimensional spin transistor, in which spin currents were generated by an electric current through graphene. The device also include a monolayer transition metal dichalcogenide (TMD) that is placed on the graphene to induce charge-to-spin conversion.
Graphene is an excellent spin transporter, but spin-orbit coupling is required to create or manipulate spins. The interaction is weak in the graphene carbon atoms, but now the researchers have shown that adding the TMD layer increases the spin-orbit coupling.
Researchers from Spain's ICN2, in collaboration with Imec and K.U. Leuven have developed a modified graphene-based nanodevice fabrication technique that can increase the spin lifetime and relaxation length by up to three times.
The researchers used CVD-made graphene grown on a platinum foil. By optimizing several standard processes, the researchers managed to reduce the impurity level of the graphene.
Researchers from two FLEET universities in Australia, RMIT and UNSW, collaborated in a theoretical–experimental project that discovered a previously unseen mode of giant magneto-resistance (GMR) in 2D Fe3GeTe2 (FGT). This surprising result suggests a different underlying physical mechanisms in vdW hetero-structures.
The research shows that vdW materials (2D material) could offer higher functionaly cmopared to traditional spintronic approaches.
Researchers from the University of Texas at San Antonio (UTSA) have developed a graphene-based "zero-power" interconnect that can present the loss of spin in Spintronics devices.
In the new architecture, the graphene nanomaterials are used as both the spin transport channel and the tunnel barrier. The researchers use reduced graphene oxide in a single-layer configuration. The researchers discovered that by controlling the amount of oxide on the graphene layers, the tune electrons’ conductivity can be fine-tuned.