Electron spin can be used to reduce contact resistance in graphene electronics

May 22, 2017

Researchers from the NUS discovered that manipulating the electron spin lowers the contact resistance in graphene electronics.

Spin filtering in metal-graphene interfaces image

Graphene is an excellent conductor, but metal-graphene interfaces suffer from large electrical resistance. The researchers have shown that edga-contacted device geometries in metallic-graphene interfaces feature some of the lowest contact resistances reported to date - significantly lower than in surface-contracted interfaces. The researchers explain that this is due to the different behavior of electron spins in these geometries.

NRL researchers produce spin-filtering at room temperature

Dec 22, 2016

Researchers from the US Naval Research Laboratory (NRL) demonstrated metallic spin filtering at room temperatures, using a ferromagnet-graphene-ferromagnet thin film junction device.

Spin filtering graphene junction (NRL)

Spin filtering has been theoretically predicted, and previously seen only for high-resistance structures at cryogenic temperatures. This is the first time that someone demonstrated the effect in room temperatures, and with very low resistance in arrays of multiple devices.

A lateral electric field can control the spin polarization in zigzag graphene ribbons

Nov 16, 2016

Researchers from Grennole Alpes University in France have demonstrated using atomistic calculations that a lateral electric field can be used to tune the carrier mobility and change the spin polarization of the current driving through zigzag graphene ribbons. The researchers say that these effects can be nicely exploited in spintronics devices.

Spin polarization in ZGNR image

The calculations predict a high variation of the carrier mobility, mean free path and spin polarization in the ZGNRs. It turns out that configurations with almost 100% spin-polarized current can be switched on and off.

Perfect zigzag-edged graphene ribbons highly attractive for Spintronics applications?

Mar 30, 2016

Researchers have succeeded, for the first time, in producing graphene nanoribbons (GNRs) with perfect zigzag edges. Electrons on these zigzag edges exhibit different (and coupled) rotational spin - which means they could be highly attractive for next-gen Spintronics devices.

GNRs with eprfect zigzag edges image

In their work, the research team describes how it managed to synthesize GNRs with perfectly zigzagged edges using suitable carbon precursor molecules and a perfected manufacturing process. The zigzags followed a very specific geometry along the longitudinal axis of the ribbons.

Graphene coated cobalt to greatly benefit spintronic devices

Dec 23, 2015

Researchers from France's Joseph Fourier University discovered that coating a cobalt film in graphene could double the film's perpendicular magnetic anisotropy (PMA), so that it reaches a value 20 times higher than that of traditional metallic cobalt/platinum multilayers.

Graphene coated cobalt to greatly benefit spintronic devices image

High-PMA materials are being researched for their applications in next-generation spintronic devices.

New room-temperature tunnel device developed using graphene as tunnel barrier and transport channel

Jul 17, 2015

Researchers from the U.S. Naval Research Laboratory (NRL) developed a new type of room-temperature tunnel device structure in which the tunnel barrier and transport channel are both made of graphene.

NRL scientists use graphene as tunnel barrier for spintronics image

In this new design, hydrogenated graphene acts as a tunnel barrier on another layer of graphene for charge and spin transport. The researchers demonstrated spin-polarized tunnel injection through the hydrogenated graphene, and lateral transport, precession and electrical detection of pure spin current in the graphene channel. The team sasy that the spin polarization values are higher than those found using more common oxide tunnel barriers, and spin transport at room temperature.