Nav: Home

A new magnetoresistance effect occurring in materials with strong spin-orbit coupling

January 26, 2016

Researchers of the Nanodevices group, in collaboration with groups from the CFM and DIPC, both institutions also located in Donostia-San Sebastián, have discovered a new magnetoresistance effect occurring in materials with strong spin-orbit coupling. This new effect has been recently reported in the prestigious journal Physical Review Letters and featured as an Editor's Suggestion.

These materials, which include metals such as platinum or tantalum, are characterized for being capable of generating a spin current from an electrical current (and viceversa) by means of the so-called spin Hall effect. For this reason, these materials are of outmost importance in the field of spintronics -the branch of science that is devoted to explore the generation, transmission and detection of spin currents in materials and devices. The ultimate goal of spintronics is to have a deeper understanding of the charge-to-spin conversion and transport phenomena at the nanoscale in order to be able to design new functional and efficient devices that are not only based on the injection, transport and storage of electrical charge, but also to its spin, which could revolutionize the conventional electronics and expand its limits. The researchers show that, by means of this novel magnetoresistive effect, it is now possible to study the spin transport properties in these materials without the need to fabricate complex devices and/or involve interfaces between different materials.

When an electric current is applied to a thin film of a material with strong spin-orbit coupling (typically of a few nanometers thick), a spin current is generated in the transverse direction -that is, along the thickness of the film- via the direct spin Hall effect, which in turn produces an electric current (via the inverse spin Hall effect) that adds to the initial applied current. This effect -small since it is due to a second-order correction-, causes a reduction in the resistivity of the film, and is maximum when the film thickness is on the order of to the spin diffusion length -that is, the average distance that a spin can travel through the material without suffering a collision that may cause a change in its state. If a magnetic field is applied not collinear to the direction where the spins points to, one can force them to precess -via the so-called Hanle effect-, thereby generating a modulation in the resistivity of the material. According to Saul Velez, first author of the work, "this new phenomenon could open ahead the possibility to study the spin transport in materials and systems not yet explored". "This new effect also allows to study the spin transport properties of known materials, and to compare the results with the ones obtained with other techniques or devices", adds Fèlix Casanova, last author and supervisor of the work.
-end-


Elhuyar Fundazioa

Related Spintronics Articles:

Patented concept from Halle: novel, high-performance diodes and transistors
Today's computer processors are increasingly pushed to their limits due to their physical properties.
Spintronics: Physicists discover new material for highly efficient data processing
A new material could aid in the development of extremely energy efficient IT applications.
Researchers get first microscopic look at a tiny phenomenon with big potential implications
Matter behaves differently when it's tiny. At the nanoscale, electric current cuts through mountains of particles, spinning them into vortexes that can be used intentionally in quantum computing.
A novel graphene-matrix-assisted stabilization method will help unique 2D materials to become a part
Scientists from Russia and Japan found a way of stabilizing two-dimensional copper oxide (CuO) materials by using graphene.
Unlocking magnetic properties for future faster, low-energy spintronics
An Australian collaboration combines theory and experimental expertise, discovering new magnetic properties of two-dimensional Fe3GeTe2 (FGT) towards spintronic applications promising faster, more efficient computing.
More Spintronics News and Spintronics Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...