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Primeur weekly 2017-09-04

Special

ETP4HPC to lay out roadmap for tangible HPC products within Europe ...

Focus

Primeur Magazine team unveils the largest directory of HPC organisations in the universe ...

Primeur Magazine team unveils the largest directory of HPC organisations in the universe ...

Quantum computing

First quantum annealing computer in the U.S. to have more than 2000 qubits installed and operational ...

Is the world on the brink of a computing revolution? - Quantum computing at the 5th Heidelberg Laureate Forum ...

Focus on Europe

Smart tomographic sensors control industrial processes of tomorrow ...

DeepL to launch DeepL Translator ...

Middleware

Learning Database speeds queries from hours to seconds ...

Unifying statistics, computer science, and applied mathematics ...

New theorems help robots to correct errors on-the-fly and learn from each other ...

Ace Computers delivers BeeGFS parallel file system for supercomputers ...

Embry-Riddle Aeronautical University acquires Cray CS cluster supercomputer to advance aerospace research ...

Hardware

ScaleMP completes $10 million funding round to accelerate growth ...

Optalysys and Earlham Institute demonstrate results of breakthrough optical processing for sequence alignment ...

University of Southern Mississippi gains campus-wide HPC cluster for research ...

Applications

New boarding procedures, smaller cabin size may limit infection on planes ...

Shaden Smith and Yang You announced as recipients of 2017 ACM/IEEE-CS George Michael Memorial HPC Fellowships ...

A new cosmic lab to view the Big Bang movie ...

Optical control of magnetic memory - New insights into fundamental mechanisms ...

Machine-learning earthquake prediction in lab shows promise ...

Caching system could make data centres more energy efficient ...

Supercomputing the weather with Thor ...

The Cloud

VMware and Dell EMC partner to deliver first data protection solution for VMware Cloud on AWS ...

Oracle expands IoT Cloud portfolio, enabling customers to accelerate intelligence and ROI from connected assets ...

VMware advances software to help customers modernize data centres ...

Fujitsu and VMware extend global partnership to empower organisations' digital transformations ...

VMware and AWS announce initial availability of VMware Cloud on AWS ...

VMware and Pivotal launch Pivotal Container Service (PKS) and collaborate with Google Cloud to bring Kubernetes to enterprise customers ...

Optical control of magnetic memory - New insights into fundamental mechanisms


This is a schematic of the experimental set-up for PEEM, the laser optics integrated sample holder and the sample. Credit: HZB.
28 Aug 2017 Berlin - A research team at Helmholtz-Zentrum Berlin (HZB) has shown for the first time how laser modulation of magnetic properties in materials is influenced by thermal effects and how the process occurs under moderate experimental parameters. At the same time, the scientists discovered a previously unknown dependence on the thickness of the magnetic layer. This is an important clue for our theoretical understanding of optically controlled magnetic data storage media. The findings are published at August 25th in the journalScientific Reports.

The demands placed on digital storage media are continuously increasing. Rapidly increasing quantities of data and new technological applications demand memory that can store large amounts of information in very little space and permit this information to be utilised dependably with high access speeds.

Re-writeable magnetic data storage devices using laser light appear to have especially good prospects. Researchers have been working on this new technology for several years. "However, there are still unresolved questions about the fundamental mechanisms and the exact manner in which optically controlled magnetic storage devices operate", stated Dr. Florian Kronast, assistant head of the Materials for Green Spintronics department at the Helmholtz-Zentrum Berlin (HZB).

A research team led by him has now succeeded in making an important step toward better understanding of this very promising storage technology. The scientists were able to empirically establish for the first time that the warming of the storage material by the energy of the laser light plays an instrumental role when toggling the magnetisation alignments and that the change in the material only takes place under certain conditions.

The HZB scientists together with those of Freie Universität Berlin and Universität Regensburg studied the microscopic processes at extremely high resolution while irradiating a thin layer of magnetic material using circularly polarised laser light. To do this, they directed the light of an infrared laser onto a nanometre-thick layer of alloy made from the metals terbium and iron (TbFe). What was special about the experimental set-up was that the narrowly focused spot of laser light had a diameter of only three microns. "That is far less than was usual in prior experiments", stated HZB scientist Ashima Arora, first author of the study. And it provided the researchers with unsurpassed detail resolution for studying the phenomena. The images of the magnetic domains in the alloy that the team created with the help of X-rays from the BESSY II synchrotron radiation source revealed fine features that themselves were only 30 nanometres in size.

The results of the measurements prove that a ring-shaped region forms around the tiny laser spot and separates the two magnetically contrasting domains from one another. The extant magnetisation pattern inside the ring is completely erased by the thermal energy of the laser light. Outside the ring, however, it remains in its original state. Within the boundary zone itself, a temperature distribution arises that facilitates a change in magnetisation by displacing the domain boundaries. "It is only there that the toggling of magnetic properties can proceed, permitting a device to store re-writeable data", explained Ashima Arora.

"These new insights will assist in the development of optically controlled magnetic storage devices having the best possible properties", in the view of Dr. Florian Kronast. An additional effect contributes to better understanding the physical processes that are important in this phenomenon, which researchers at HZB unexpectedly observed for the first time. The way the toggling of the magnetisations happens is highly dependent on the layer thickness of the material irradiated by the laser. It changes over an interval of 10 to 20 nanometres thickness.

"This is a clear indication that two contrasting mechanisms are involved and compete with one another", Dr. Florian Kronast explained. He and his team suspect two complex physical effects for this. To confirm their suspicions, though, further empirical and theoretical studies are necessary.

The findings are published inScientific Reports- DOI 10.1038/s41598-017-09615-1: " Spatially resolved investigation of all optical magnetization switching in TbFe alloys ". This paper is authored by Ashima Arora, Mohammad-Assaad Mawass, Oliver Sandig, Chen Luo, Ahmet A. Ünal, Florian Radu, Dergio Valencia, and Florian Kronast.
Source: Helmholtz-Zentrum Berlin für Materialien und Energie

Back to Table of contents

Primeur weekly 2017-09-04

Special

ETP4HPC to lay out roadmap for tangible HPC products within Europe ...

Focus

Primeur Magazine team unveils the largest directory of HPC organisations in the universe ...

Primeur Magazine team unveils the largest directory of HPC organisations in the universe ...

Quantum computing

First quantum annealing computer in the U.S. to have more than 2000 qubits installed and operational ...

Is the world on the brink of a computing revolution? - Quantum computing at the 5th Heidelberg Laureate Forum ...

Focus on Europe

Smart tomographic sensors control industrial processes of tomorrow ...

DeepL to launch DeepL Translator ...

Middleware

Learning Database speeds queries from hours to seconds ...

Unifying statistics, computer science, and applied mathematics ...

New theorems help robots to correct errors on-the-fly and learn from each other ...

Ace Computers delivers BeeGFS parallel file system for supercomputers ...

Embry-Riddle Aeronautical University acquires Cray CS cluster supercomputer to advance aerospace research ...

Hardware

ScaleMP completes $10 million funding round to accelerate growth ...

Optalysys and Earlham Institute demonstrate results of breakthrough optical processing for sequence alignment ...

University of Southern Mississippi gains campus-wide HPC cluster for research ...

Applications

New boarding procedures, smaller cabin size may limit infection on planes ...

Shaden Smith and Yang You announced as recipients of 2017 ACM/IEEE-CS George Michael Memorial HPC Fellowships ...

A new cosmic lab to view the Big Bang movie ...

Optical control of magnetic memory - New insights into fundamental mechanisms ...

Machine-learning earthquake prediction in lab shows promise ...

Caching system could make data centres more energy efficient ...

Supercomputing the weather with Thor ...

The Cloud

VMware and Dell EMC partner to deliver first data protection solution for VMware Cloud on AWS ...

Oracle expands IoT Cloud portfolio, enabling customers to accelerate intelligence and ROI from connected assets ...

VMware advances software to help customers modernize data centres ...

Fujitsu and VMware extend global partnership to empower organisations' digital transformations ...

VMware and AWS announce initial availability of VMware Cloud on AWS ...

VMware and Pivotal launch Pivotal Container Service (PKS) and collaborate with Google Cloud to bring Kubernetes to enterprise customers ...