Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

When electric fields make spins swirl

15.11.2018

First example of ferroelectrically tunable skyrmions brings new hope for next-generation magnetic memory devices

We are reaching the limits of silicon capabilities in terms of data storage density and speed of memory devices. One of the potential next-generation data storage elements is the magnetic skyrmion.


This study measured skyrmions in an ultra-thin material made of a ferromagnetic layer of strontium ruthenate (SrRuO3), overlaid with a ferroelectric layer of barium titanate (BaTiO3) and grown on a strontium titanate (SrTiO3) substrate. BaTiO3 is ferroelectric, meaning that it has a switchable and permanent electric polarization (), while SrRuO3 is ferromagnetic below 160 Kelvin (-113 Celsius). At the BaTiO3/SrRuO3 interface, the BaTiO3 ferroelectric polarization swirls the spins in SrRuO3, generating skyrmions. If the researchers flip the direction of polarization in BaTiO3, the density of the skyrmions changes.

Credit: IBS


While ferromagnets have their spins (magnetic moments, represented as arrows) aligned uniformly in a parallel fashion, magnetic skyrmions are formed by spins arranged in a whirl shape.

Credit: IBS

A team at the Center for Correlated Electron Systems, within the Institute for Basic Science (IBS, South Korea), in collaboration with the University of Science and Technology of China, have reported the discovery of small and ferroelectrically tunable skyrmions. Published in Nature Materials, this work introduces new compelling advantages that bring skyrmion research a step closer to application.

It is envisioned that storing memory on skyrmions - stable magnetic perturbations of whirling spins (magnetic moments) - would be faster to read and write, consume less energy, and generate less heat than the currently used magnetic tunnel junctions.

In future memory and logic devices, 1 and 0 bits would correspond to the existence and non-existence of a magnetic skyrmion, respectively. Although numerous skyrmion systems have been discovered in laboratories, it is still very challenging to produce controllable, nanometer-sized skyrmions for our technology needs.

In this study, the researchers found out that skyrmions with a diameter smaller than 100 nanometers spontaneously form in ultrathin material, consisting of a layer of barium titanate (BaTiO3) and a layer of strontium ruthenate (SrRuO3). Below 160 Kelvin (-113 Celsius), SrRuO3 is ferromagnetic, meaning that its spins are aligned uniformly in a parallel fashion.

When the two layers are overlaid, however, a special magnetic interaction swirls SrRuO3's spins, generating magnetic skyrmions. Such peculiar magnetic structure was detected below 80 Kelvin (-193 Celsius) by using magnetic force microscopy and Hall measurements.

In addition, by manipulating the ferroelectric polarization of the BaTiO3 layer, the team was able to change the skyrmions' density and thermodynamic stability. The modulation is non-volatile (it persists when the power is turned off), reversible, and nanoscale.

"Magnetic skyrmions and ferroelectricity are two important research topics in condensed matter physics. They are usually studied separately, but we brought them together," explains Lingfei Wang, first author of the study.

"This correlation provides an ideal opportunity to integrate the high tunability of well-established ferroelectric devices with the superior advantages of skyrmions into next-generation memory and logic devices."

Media Contact

Dahee Carol Kim
clitie620@ibs.re.kr
82-428-788-133

 @IBS_media

http://www.ibs.re.kr/en/ 

Dahee Carol Kim | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41563-018-0204-4

More articles from Physics and Astronomy:

nachricht Harvesting energy from the human knee
17.07.2019 | American Institute of Physics

nachricht Neutrino-Observatorium IceCube am Südpol wird ausgebaut
17.07.2019 | Deutsches Elektronen-Synchrotron DESY

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

Im Focus: Modelling leads to the optimum size for platinum fuel cell catalysts: Activity of fuel cell catalysts doubled

An interdisciplinary research team at the Technical University of Munich (TUM) has built platinum nanoparticles for catalysis in fuel cells: The new size-optimized catalysts are twice as good as the best process commercially available today.

Fuel cells may well replace batteries as the power source for electric cars. They consume hydrogen, a gas which could be produced for example using surplus...

Im Focus: The secret of mushroom colors

Mushrooms: Darker fruiting bodies in cold climates

The fly agaric with its red hat is perhaps the most evocative of the diverse and variously colored mushroom species. Hitherto, the purpose of these colors was...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

For bacteria, the neighbors co-determine which cell dies first: The physiology of survival

17.07.2019 | Life Sciences

Harvesting energy from the human knee

17.07.2019 | Physics and Astronomy

Neutrino-Observatorium IceCube am Südpol wird ausgebaut

17.07.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>