Important prerequisite for the development of nano-components for data storage and sensor technology / Publication in Nature Communications
Researchers at Johannes Gutenberg University Mainz (JGU) have achieved a major breakthrough in the development of methods of information processing in nanomagnets. Using a new trick, they have been able to induce synchronous motion of the domain walls in a ferromagnetic nanowire.
This involved applying a pulsed magnetic field that was perpendicular to the plane of the domain walls. "This is a radically new solution," explained Professor Mathias Kläui of the Institute of Physics of Johannes Gutenberg University Mainz. "It enables us to move domain walls synchronously over a relatively large distance without them returning to their original position."
This is essential for permanent data storage, because data would otherwise be lost if domain walls were not collectively displaced in a controlled manner. The research was carried out in cooperation with the working groups of Professor Stefan Eisebitt at TU Berlin and Professor Gisela Schütz of the Max Planck Institute for Intelligent Systems in Stuttgart. The results were published in the journal Nature Communications at the end of March.
Magnetic nanowires have small regions of uniform magnetization called domains, which can be used as storage units (bits). The site where domains of different alignment meet each other is called a domain wall. Information can be stored in the domain, and read and processed by means of the movement of the domain walls.
The method has the great advantage that the information – as in the case of magnetic data storage in general – cannot be easily lost. This contrasts with semiconductor-based storage systems, such as RAM in PCs, which lose all stored information without power. In addition, no fragile moving parts are required such as the read/write head of a hard disk.
It has not previously proved possible to induce the required controlled and synchronized movement of multiple domain walls using magnetic fields. The most obvious approach would be to apply a magnetic field in the direction in which the magnetization runs in the tiny nanowires. However, this has been shown to be ineffective, as there is loss of data. Mathias Kläui and his group took a radically new path.
They decided to apply a pulsed magnetic field perpendicularly to the in-plane magnetized domain walls. As the Mainz researchers found in their model system, it is possible to customize the asymmetric field pulses that provide the forward- and backward-oriented forces that act on domain walls. Data can thus be moved within the storage medium in a controlled manner.
The participating physicists at Mainz University first tried out their concept in the context of micromagnetic simulations and then tested it experimentally. For this purpose, they recorded images of the magnetic arrangement in the tiny nanowires with the help of the electron storage ring BESSY II of the Helmholtz Center Berlin for Materials and Energy (HZB).
As expected from the simulation, they observed displacement of the domain walls in a direction that was consistent with the model. The scientists also calculated the energy that would be necessary for the experimentally observed domain wall motion and came to the conclusion that the energy consumption of the proposed system would be quite cost-effective compared with the best components currently available.
"The results are very promising. We assume that the necessary paradigm shift will be facilitated by this new approach and it will prove possible to develop a method of efficient and controlled synchronous motion of the domain walls in nanowires," said Kläui. This would pave the way for the development of non-volatile spintronic components of the next generation, which could be used in a wide range of applications for data storage as well as logic and sensor modules.
June-Seo Kim et al.
Synchronous precessional motion of multiple domain walls in a ferromagnetic nanowire by perpendicular field pulses
Nature Communications, 24 March 2014
Prof. Dr. Mathias Kläui
Theory of Condensed Matter
Institute of Physics
Johannes Gutenberg University Mainz (JGU)
D 55099 Mainz, GERMANY
phone +49 6131 39-23633
http://www.uni-mainz.de/presse/17186_ENG_HTML.php - press release ;
http://www.nature.com/ncomms/2014/140324/ncomms4429/full/ncomms4429.html - publication
Petra Giegerich | idw - Informationsdienst Wissenschaft
Theory of the strong interaction verified
27.03.2015 | Forschungszentrum Juelich
Dark matter even darker than once thought
27.03.2015 | ESA/Hubble Information Centre
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
27.03.2015 | Agricultural and Forestry Science
27.03.2015 | Materials Sciences
27.03.2015 | Ecology, The Environment and Conservation