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Primeur weekly 2013-08-12

Special

Hybrid architectures and stream computing are becoming the norm in life sciences ...

Focus

UberCloud successful in bringing HPC Cloud to SMEs - and interview with Wolfgang Gentzsch ...

The Cloud

New IBM Flex Systems allow clients to build larger Clouds in smaller data centres ...

Orion Health chooses HP to support managed health services ...

Oracle Enterprise Manager 12c delivers comprehensive management for Oracle Database 12c ...

Capitalonline taps IBM to offer enhanced Cloud services ...

IBM to help Geraldton become smarter, more sustainable city with new Cloud data centre ...

Adaptive Computing unveils Moab Cloud Optimizer Integration for HP Cloud Service Automation 3.2 ...

EuroFlash

Putting Big Data into Perspective ...

Magnetic switching simplified ...

Quantum communication controlled by resonance in 'artificial atoms' ...

Skoda Auto selects SGI ICE X and SGI UV 2000 HPC systems to accelerate automotive innovation ...

ClusterVision strengthens commercial teams in the UK and Germany ...

Wroclaw University Library turns to IBM Big Data solution to preserve European heritage, open digital archives to the world ...

USFlash

Fujitsu receives order for new supercomputer system from Canon ...

IBM Research creates new foundation to program SyNAPSE chips ...

Google, IBM, Mellanox, NVIDIA, and Tyan announce development group for data centres ...

HP helps New Zealand Government Council boost employee productivity ...

Cray names John Josephakis Vice President of Worldwide Sales ...

CSIRO takes charge of Australia's information overload ...

Supercomputer-enabled metagenomic research explores ecosystems in oceans and microbes in the human esophagus ...

Speed limit set for ultrafast electrical switch ...

SGI reports fourth quarter and fiscal year 2013 financial results ...

NVIDIA reports financial results for second quarter fiscal 2014 ...

How superbug spreads among regional hospitals: a domino effect ...

Magnetic switching simplified


Forschungszentrum Jülich
7 Aug 2013 Jülich - An international team of researchers has described a new physical effect that could be used to develop more efficient magnetic chips for information processing. The quantum mechanical effect makes it easier to produce spin-polarized currents necessary for the switching of magnetically stored information. The research findings were published on-line on 28 July in the high-impact journalNature Nanotechnology(DOI:10.1038/NNANO.2013.145).

Random-access memory is the short-term memory in computers. It buffers the programmes and files currently in use in electronic form, in numerous tiny capacitors. As capacitors discharge over time, they have to be recharged regularly to ensure that no data are lost. This costs time and energy, and an unplanned power failure can result in data being lost for good.

Magnetic Random Access Memories (MRAMs), on the other hand, store information in tiny magnetic areas. This is a fast process that functions without a continuous power supply. In spite of this, MRAMs have yet to be implemented on a large scale, as their integration density is still too low, and they use too much energy, are difficult to produce, and cost too much.

One reason for this is that spin-polarized currents, or spin currents for short, are needed to switch the magnetic areas of the MRAMs. Spin is the intrinsic angular momentum of electrons that gives materials their magnetic properties, and it can point in two directions. Spin currents are electric currents that possess only one of these two spin types. Similar to the way in which the Earth's magnetic field affects the needle of a compass, a current of one of the spin types influences a magnetic layer and can cause it to flip.

To produce spin currents up to now, the desired spin type was filtered from normal electric current. This required special filter structures and high current densities. Thanks to the new effect identified by researchers from Jülich, Barcelona, Grenoble, and Zurich, magnetic information could now be switched more easily.

"We no longer need spin filters. Instead, we produce the spin current directly where it will be used. All that is needed is a layer stack made of cobalt and platinum", stated Dr. Frank Freimuth from the Peter Grünberg Institute and the Institute for Advanced Simulation at Forschungszentrum Jülich. This reduces the amount of space required, makes the system more robust, and may simplify the production of magnetic chips.

An electric current, conducted through the stack at the interface, separates the spins in the platinum layer and transports only one spin type into the magnetic cobalt layer. This creates a torque in this layer that can reverse the magnetization. "Spin torques had already been observed in double layer systems in the past", stated the physicist, who is part of the Young Investigators Group on Topical Nanoelectronics headed by Prof. Yuriy Mokrousov. "The fact that we have conclusively explained for the first time how they are created is a scientific breakthrough, because this will enable us to produce them selectively and investigate them in more detail."

The researchers identified two mechanisms that combine to produce the new effect, which they have dubbed 'spin-orbit torque': spin-orbit coupling and the exchange interaction. Spin-orbit coupling is a well-known relativistic quantum phenomenon and the reason why all electron spins of one type move from the platinum to the cobalt layer. Within the cobalt layer, the layer's magnetic orientation then interacts with the spins via the exchange interaction.

The researchers tested their theory successfully in experiments. Their next step is to calculate the effect in other materials with stronger spin-torque coupling to find out whether the effect is even more apparent in other material combinations.

The original publication, "Symmetry and magnitude of spin-orbit torques in ferromagnetic heterostructures" by K. Garello et al. appears inNature Nanotechnolog, published on-line 28 July 2013; DOI:10.1038/NNANO.2013.145.
Source: Helmholtz Association

Back to Table of contents

Primeur weekly 2013-08-12

Special

Hybrid architectures and stream computing are becoming the norm in life sciences ...

Focus

UberCloud successful in bringing HPC Cloud to SMEs - and interview with Wolfgang Gentzsch ...

The Cloud

New IBM Flex Systems allow clients to build larger Clouds in smaller data centres ...

Orion Health chooses HP to support managed health services ...

Oracle Enterprise Manager 12c delivers comprehensive management for Oracle Database 12c ...

Capitalonline taps IBM to offer enhanced Cloud services ...

IBM to help Geraldton become smarter, more sustainable city with new Cloud data centre ...

Adaptive Computing unveils Moab Cloud Optimizer Integration for HP Cloud Service Automation 3.2 ...

EuroFlash

Putting Big Data into Perspective ...

Magnetic switching simplified ...

Quantum communication controlled by resonance in 'artificial atoms' ...

Skoda Auto selects SGI ICE X and SGI UV 2000 HPC systems to accelerate automotive innovation ...

ClusterVision strengthens commercial teams in the UK and Germany ...

Wroclaw University Library turns to IBM Big Data solution to preserve European heritage, open digital archives to the world ...

USFlash

Fujitsu receives order for new supercomputer system from Canon ...

IBM Research creates new foundation to program SyNAPSE chips ...

Google, IBM, Mellanox, NVIDIA, and Tyan announce development group for data centres ...

HP helps New Zealand Government Council boost employee productivity ...

Cray names John Josephakis Vice President of Worldwide Sales ...

CSIRO takes charge of Australia's information overload ...

Supercomputer-enabled metagenomic research explores ecosystems in oceans and microbes in the human esophagus ...

Speed limit set for ultrafast electrical switch ...

SGI reports fourth quarter and fiscal year 2013 financial results ...

NVIDIA reports financial results for second quarter fiscal 2014 ...

How superbug spreads among regional hospitals: a domino effect ...