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.
Irati Kortabitarte | EurekAlert!
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine