Researchers show how to create spin-valley half-metals

Sep 17, 2017

Researchers from Russia and Japan have shown, theoretically, that it is possible to create a new class of materials: spin-valley half-metals. These kind of devices could enable both spintronics valleytronics applications.

Spin-valley half-metal image (MIPT)

In "regular" half-metals, all the electrons that participate in electric currents have the same spin - and so the current is always spin-polarized. These materials have interesting applications for spintronics devices. In the new class of materials now proven theoretically to be possible, there are two valleys present - one providing electrons, one providing holes.

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.

JGU establishes a new spintronics junior research group

Oct 13, 2016

The Johannes Gutenberg University Mainz (JGU), with funding from the German Research Foundation (DFG), is setting up an Emmy Noether independent junior research group to study spintronics.

Skyrmions generated by hairy balls image

Specifically, the TWIST (Topological Whirls in SpinTronics) work group will study skyrmions - magnetic "particles" or nodes within a magnetic texture. Skyrmions are more stable than other magnetic structures and react particularly readily to spin currents - which makes them interesting for spintronics applications.

Laser pulses can be used to create strong spin currents

Jun 02, 2016

Researchers from TU Wien designed a method to create extremely strong spin currents using ultra-short laser pulses.

Laser pulse hits nickel on silicon photo

Using computer simulations, the researchers discovered that when short laser pulses hit a thin layer of nickel on a silicon substrate, the electrons accelerate toward the silicon, which builds an electric field on the interface of the two materials. This stops the current, but the spin is still transported. the spin-up electrons move freely, while the spin-down electrons have a much higher probability of being scattered at the nickel atoms. This creates many spin-up electrons in the silicon - effectively creating a spin current in the silicon.

Researchers detect magnetic fluctuations with pure spin current

Dec 17, 2015

Researchers from Japan and France managed to detect magnetic fluctuations with pure spin current. This has been done in a much more sensitive way than conventional magnetization measurements.

Spin-charge conversion in a spin glass system image

The researchers used spin glass, a typical frustrated system where a small amount of impurities with magnetic moments is randomly distributed in a nonmagnetic host metal. At high temperatures, the magnetic moments are fluctuating with a very high speed. As the temperature approaches the spin glass temperature (Tg), the fluctuations become slower and then the magnetic moments are frozen at Tg.

Researchers discover that pure-spin current is possible in insulators

Jul 27, 2015

Researchers from the US DoE's Argonne National Laboratory discovered that a pure-spin current can be created in materials that are insulators. Previously it was thought that such a current is possible in magnetic materials only.

SSE in Paramagnets image

The researchers generated a magnetic field on a layer of ferromagnetic YIG (yttrium iron garnet) on a substrate of paramagnetic GGG (gadolinium gallium garnet). To their surprise, the spin current was stronger in the GGG than it was in the YIG. They actually do not know how this works - and understanding it is the next step in their research.