Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Origin of ultra-fast manipulation of domain walls discovered

Research success for the international research team including a fellow of the MAINZ Graduate School of Excellence

An international team of researchers has found at the free electron laser FLASH a surprising effect that leads in ferromagnetic materials to a spatially varying magnetization manipulation on an ultrafast timescale.

Magnetic force microscopy image of a 10µm X 10µm sized sample showing a labyrinth-type magnetic domain structure. The magnetization is oriented perpendicularly to the surface (white: magnetization pointing out of the plane; brown: magnetization pointing into the plane).

photo/©: Bastian Pfau, TU Berlin

This effect could be the key to further miniaturization and performance increase of magnetic data storage devices. From Mainz, the group of Professor Dr. Mathias Kläui from the Institute of Physics at Johannes Gutenberg University Mainz and in particular Felix Büttner, a member of the Graduate School of Excellence "Materials Science in Mainz", were involved. The results have been published in the current issue of Nature Communications.

It is known that magnetization can be manipulated by short light pulses but so far the spatially-resolved magnetization change could not be determined due to the limited spatial resolution of conventional optical techniques. Since most of the ferromagnetic materials consist of multiple domains with different magnetization directions, the local change of the magnetization in these domains and at the interfaces between the domains, i.e. at the so-called domain walls, is of particular interest.

At the FLASH free electron laser at the DESY Research Center in Hamburg, results were obtained that are in agreement with a recently theoretically predicted mechanism: due to the laser pulses, highly excited electrons are generated that move quickly through the material. They thus move from one domain into a neighboring domain with a different magnetization direction. Since the electrons carry part of the magnetization, they manipulate the magnetization in the domains as they move across a domain wall. This means that domain walls can change their geometry on the fs time scale.

As domain walls are also used in memory devices, such as the racetrack memory, these investigations could be the first step to improving the performance of such devices. The racetrack memory is a development by IBM and could in the future be a fast and low power alternative to conventional random access memory or hard drives.

The experiments were carried out by the researchers from Johannes Gutenberg University Mainz (JGU) with colleagues from TU Berlin, the universities of Hamburg and Paris, and six further research institutes at the free electron laser FLASH at DESY in Hamburg. The samples investigated consist of a cobalt-platinum multilayer system, which forms labyrinth-type domain structures.

B. Pfau et al., Ultrafast optical demagnetization manipulates nanoscale spin structure in domain walls, Nature Communications, 3:1100, 2 October 2012,

Professor Dr. Mathias Kläui
Institute of Physics
Johannes Gutenberg University
D 55099 Mainz
phone +49 6131 39-23633
fax +49 6131 39-24076

Petra Giegerich | idw
Further information:

More articles from Materials Sciences:

nachricht How nanoscience will improve our health and lives in the coming years
27.10.2016 | University of California - Los Angeles

nachricht 3-D-printed structures shrink when heated
26.10.2016 | Massachusetts Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>