Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Physicists measure current-induced torque in nonvolatile magnetic memory devices


The geometry of a magnetic tunnel junction.
The geometry of a magnetic tunnel junction.

Abstract:
Tomorrow's nonvolatile memory devices -- computer memory that can retain stored information even when not powered -- will profoundly change electronics, and Cornell researchers have discovered a new way of measuring and optimizing their performance.

Physicists measure current-induced torque in nonvolatile magnetic memory devices

Ithaca, NY | Posted on March 9th, 2011

Using a very fast oscilloscope, researchers led by Dan Ralph, the Horace White Professor of Physics, and Robert Buhrman, the J.E. Sweet Professor of Engineering, have figured out how to quantify the strength of current-induced torques used to write information in memory devices called magnetic tunnel junctions. The results were published online Feb. 27 in the journal Nature Physics.

Magnetic tunnel junctions are memory storage devices made of a sandwich of two ferromagnets with a nanometers-thick oxide insulator in between. The electrical resistance of the device is different for parallel and nonparallel orientations of the magnetic electrodes, so that these two states create a nonvolatile memory element that doesn't require electricity for storing information. An example of nonvolatile memory today is flash memory, but that is a silicon-based technology subject to wearing out after repeated writing cycles, unlike magnetic memory.

What has held back magnetic memory technology is that it has required magnetic fields to switch the magnetic states -- that is, to write information. This limits their size and efficiency because magnetic fields are long-ranged and relatively weak, so large currents and thick wires are needed to generate a large-enough field to switch the device.

The Cornell researchers are studying a new generation of magnetic devices that can write information without using magnetic fields. Instead, they use a mechanism called "spin torque," which arises from the idea that electrons have a fundamental spin (like a spinning top). When the electrons interact with the magnets in the tunnel junctions, they transfer some of their angular momentum. This can provide a very strong torque per unit current, and has been demonstrated to be at least 500 times more efficient than using magnetic fields to write magnetic information, Ralph said.

To measure these spin torques, the researchers used an oscilloscope in a shared facility operated by Cornell's Center for Nanoscale Systems. They applied torque to the magnetic tunnel junctions using an alternating current and measured the amplitude of resistance oscillations that resulted. Since the resistance depends on the relative orientation of the two magnets in the tunnel junction, the size of the resistance oscillations could be related directly to the amplitude of the magnetic motion, and hence to the size of the torque.

The researchers hope such experiments will help industry make better nonvolatile memory devices by understanding exactly how to structure them, and also, what materials would best be used as the oxide insulators and the ferromagnets surrounding them.

The work was supported by the National Science Foundation, the Army Research Office and the Office of Naval Research, and included collaborators Chen Wang, graduate student and first author; graduate student Yong-Tao Cui; and Jordan A. Katine from Hitachi Global Storage Technologies.

####

For more information, please click here

Contacts:
Media Contact:
Blaine Friedlander
(607) 254-8093


Anne Ju
(607) 255-9735


Chronicle Online
312 College Ave.
Ithaca, NY 14850
607.255.4206

Copyright © Cornell University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Harris & Harris Group Portfolio Company, AgBiome, Announces Partnership to Accelerate the Discovery of Next Generation Insect-Resistant Crops July 1st, 2015

Bruker Introduces Second-Generation Inspire Nanochemical Imaging Solution: Featuring Unique PeakForce IR and IR EasyAlign Technology July 1st, 2015

GLOBALFOUNDRIES Completes Acquisition of IBM Microelectronics Business: Transaction adds differentiating technologies, world-class technologists, and intellectual property July 1st, 2015

Samsung's New Graphene Technology Will Double Life Of Your Lithium-Ion Battery July 1st, 2015

Physics

Helium 'balloons' offer new path to control complex materials June 27th, 2015

The peaks and valleys of silicon: Team of USC Viterbi School of Engineering Researchers introduce new layered semiconducting materials as silicon alternative June 27th, 2015

The quantum spin Hall effect is a fundamental property of light June 25th, 2015

Physicists fine-tune control of agile exotic materials: Tunable hybrid polaritons realized with graphene layer on hexagonal boron nitride June 24th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Proposed TSCA Nanomaterial Rule ‘Premature’, Says Former EPA Toxicologist July 1st, 2015

Carnegie Mellon chemists characterize 3-D macroporous hydrogels: Methods will allow researchers to develop new 'smart' materials June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

X-rays and electrons join forces to map catalytic reactions in real-time: New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions June 29th, 2015

Spintronics

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Spintronics advance brings wafer-scale quantum devices closer to reality June 24th, 2015

Solvent encapsulation is the trick: a solid material with spin-transition solution-like behaviour June 5th, 2015

Oxford Instruments welcomes Dr Masamitsu Hayashi, the winner of the Sir Martin Wood Science Prize for Japan, to UK June 1st, 2015

Chip Technology

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

GLOBALFOUNDRIES Completes Acquisition of IBM Microelectronics Business: Transaction adds differentiating technologies, world-class technologists, and intellectual property July 1st, 2015

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Memory Technology

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Buckle up for fast ionic conduction June 16th, 2015

A KAIST research team develops the first flexible phase-change random access memory June 15th, 2015

Discoveries

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Measurement of Tiny Amounts of Heavy Metals in Baby Food Samples July 1st, 2015

Chitosan coated, chemotherapy packed nanoparticles may target cancer stem cells June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Announcements

Leti Announces Launch of First European Nanomedicine Characterisation Laboratory: Project Combines Expertise of 9 Partners in 8 Countries to Foster Nanomedicine Innovation and Facilitate Regulatory Approval July 1st, 2015

Bruker Introduces Second-Generation Inspire Nanochemical Imaging Solution: Featuring Unique PeakForce IR and IR EasyAlign Technology July 1st, 2015

GLOBALFOUNDRIES Completes Acquisition of IBM Microelectronics Business: Transaction adds differentiating technologies, world-class technologists, and intellectual property July 1st, 2015

Samsung's New Graphene Technology Will Double Life Of Your Lithium-Ion Battery July 1st, 2015

Military

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

The peaks and valleys of silicon: Team of USC Viterbi School of Engineering Researchers introduce new layered semiconducting materials as silicon alternative June 27th, 2015

Opening a new route to photonics Berkeley lab researchers find way to control light in densely packed nanowaveguides June 27th, 2015

World’s 1st Full-Color, Flexible, Skin-Like Display Developed at UCF June 24th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project