Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > The synchronized dance of skyrmion spins: Computer simulations reveal new insights into skyrmion particles, which are promising for next-generation information storage and processing devices

The configuration of spins in a Néel skyrmion.
CREDIT
Zhang et al.
The configuration of spins in a Néel skyrmion. CREDIT Zhang et al.

Abstract:
In recent years, excitement has swirled around a type of quasi-particle called a skyrmion that arises as a collective behavior of a group of electrons. Because they're stable, only a few nanometers in size, and need just small electric currents to transport them, skyrmions hold potential as the basis for ultra-compact and energy-efficient information storage and processing devices in the future.

The synchronized dance of skyrmion spins: Computer simulations reveal new insights into skyrmion particles, which are promising for next-generation information storage and processing devices

Washington, DC | Posted on May 30th, 2017

Now, a research group in Singapore has used computer simulations to further probe the behaviors of skyrmions, gaining insight that can help scientists and engineers better study the quasi-particles in experiments. The new results, published this week in AIP Advances, from AIP Publishing, could also lead to skyrmion-based devices such as microwave nano-oscillators, used in a range of applications including wireless communication, imaging systems, radar and GPS.

"Its unique attributes, for instance, could theoretically enable notebooks with hard drives the size of peanuts, and yet consume little energy," said Meng Hau Kuok of the National University of Singapore and one of the work's authors.

Observed in 2009, skyrmions arise from the collective behavior of electrons in magnetic materials under certain conditions. Due to their spins, the electrons act as tiny magnets where their magnetic poles align with their spins. A phenomenon called the Dzyaloshinskii-Moriya interaction (DMI) -- which occurs at the interface between a magnetic layer and a non-magnetic metal -- tilts the spins and arranges them into circular patterns. These circular arrangements of spins, which behave collectively like particles, are skyrmions.

Although researchers have studied how groups of skyrmions behave, little is known about their internal behaviors, Kuok said. In particular, physicists don't fully understand the particles' three fundamental modes, which are analogous to the fundamental vibrational modes of a guitar string corresponding to different musical notes. Like those notes, each skyrmion mode is associated with a certain frequency.

"The modes can be thought of as circular patterns of spins dancing in sync," Kuok said. Understanding the modes is essential for knowing how the particles would behave.

In one of the modes, called the breathing mode, the pattern of spins alternately expands and contracts. In the two other modes, the circular arrangement of spins rotates in the clockwise and counterclockwise directions, respectively.

The researchers focused on a type of skyrmion called the Néel skyrmion, which exists in ultrathin films deposited on metals with a strong DMI. Using a computer, they simulated how the DMI and external magnetic fields of varying strengths affected the modes and properties of the particles. They found that given the same DMI strength, and if in the crystal phase, the frequencies corresponding to each mode depend differently on magnetic field strength.

Increasing the magnetic field also induces the skyrmions to change phase relative to one another, from being arranged in ordered arrays like a crystal to randomly distributed and isolated. The researchers found that the three modes respond differently to this phase transition.

Surprisingly, Kuok said, all three modes can exist in the crystal phase, while the clockwise rotational mode does not exist in the isolated phase. One reason, the simulations revealed, might be that the skyrmions are farther apart in the isolated phase than in the crystal phase. If the skyrmions are too far apart, then they can't interact. This interaction might be necessary for the clockwise rotational mode, Kuok said.

Because the mode frequencies of skyrmions are in the microwave range, the quasi-particles could be used for new microwave nano-oscillators, which are important building blocks for microwave integrated circuits.

A microwave nano-oscillator based on skyrmions could operate at three resonant frequencies, corresponding to the three modes. An increasing magnetic field would lower the resonant frequencies of the breathing and clockwise rotating modes at different rates, but increase the resonant frequency of the counterclockwise rotating mode. Such a skyrmion-based device would be more compact, stable, and require less energy than conventional, electron-based nano-oscillators.

But before skyrmions find their way into devices, researchers still need to engineer their specific desired properties, such as size, and precisely tune their dynamic properties. "Our findings could provide theoretical insights into addressing these challenges," Kuok said.

####

About American Institute of Physics
AIP Advances is an open access journal publishing in all areas of physical sciences--applied, theoretical, and experimental. All published articles are freely available to read, download, and share. The journal prides itself on the belief that all good science is important and relevant. Our inclusive scope and publication standards make it an essential outlet for scientists in the physical sciences.

For more information, please click here

Contacts:
Julia Majors

30-120-903-090

Copyright © American Institute of Physics

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

The article, "Eigenmodes of Néel skyrmions in ultrathin magnetic films," is authored by Vanessa L. Zhang, Chen Guang Hou, Kai Di, Hock Siah Lim, Ser Choon Ng, Shawn Pollard, Hyunsoo Yang and Meng Hau Kuok. The article appeared in AIP Advances on May 30, 2017 [DOI: 10.1063/1.4983805] and can be accessed at http://aip.scitation.org/doi/full/10.1063/1.4983806.:

Related News Press

News and information

A step closer to understanding quantum mechanics: Swansea University’s physicists develop a new quantum simulation protocol October 22nd, 2017

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Leti Coordinating Project to Develop Innovative Drivetrains for 3rd-generation Electric Vehicles: CEA Tech’s Contribution Includes Liten’s Knowhow in Magnetic Materials and Simulation And Leti’s Expertise in Wide-bandgap Semiconductors October 20th, 2017

Imaging

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Seeing the next dimension of computer chips: Researchers image perfectly smooth side-surfaces of 3-D silicon crystals with a scanning tunneling microscope, paving the way for smaller and faster computing devices October 11th, 2017

Quorum announces new customer support and demonstration facilities for users worldwide October 10th, 2017

Photoacoustic imaging and photothermal cancer therapy using BR nanoparticles September 26th, 2017

Wireless/telecommunications/RF/Antennas/Microwaves

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Columbia engineers invent breakthrough millimeter-wave circulator IC October 6th, 2017

Quantum communications bend to our needs: By changing the wavelengths of entangled photons to those used in telecommunications, researchers see quantum technology take a major leap forward September 28th, 2017

GLOBALFOUNDRIES Introduces New 12nm FinFET Technology for High-Performance Applications September 20th, 2017

Skyrmions

Fast-moving magnetic particles could enable new form of data storage: Recently discovered phenomenon could provide a way to bypass the limits to Moore's Law October 2nd, 2017

Possible Futures

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Bringing the atomic world into full color: Researchers turn atomic force microscope measurements into color images October 19th, 2017

'Find the Lady' in the quantum world: International team of researchers presents method for quantum-mechanical swapping of positions October 18th, 2017

Long nanotubes make strong fibers: Rice University researchers advance characterization, purification of nanotube wires and films October 17th, 2017

Discoveries

A step closer to understanding quantum mechanics: Swansea University’s physicists develop a new quantum simulation protocol October 22nd, 2017

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Announcements

A step closer to understanding quantum mechanics: Swansea University’s physicists develop a new quantum simulation protocol October 22nd, 2017

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Leti Coordinating Project to Develop Innovative Drivetrains for 3rd-generation Electric Vehicles: CEA Tech’s Contribution Includes Liten’s Knowhow in Magnetic Materials and Simulation And Leti’s Expertise in Wide-bandgap Semiconductors October 20th, 2017

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

A step closer to understanding quantum mechanics: Swansea University’s physicists develop a new quantum simulation protocol October 22nd, 2017

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project