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
LIGO confirms RIT's breakthrough prediction of gravitational waves
12.02.2016 | Rochester Institute of Technology
Milestone in physics: gravitational waves detected with the laser system from LZH
12.02.2016 | Laser Zentrum Hannover e.V.
Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.
The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
12.02.2016 | Event News
09.02.2016 | Event News
02.02.2016 | Event News
12.02.2016 | Physics and Astronomy
12.02.2016 | Life Sciences
12.02.2016 | Medical Engineering