Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

X-ray photoelectron spectroscopy under real ambient pressure conditions June 28th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosunís ALD solutions enable novel high-speed memories June 27th, 2017

Physics

X-ray photoelectron spectroscopy under real ambient pressure conditions June 28th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Spintronics

Smart multi-layered magnetic material acts as an electric switch: New study reveals characteristic of islands of magnetic metals between vacuum gaps, displaying tunnelling electric current March 1st, 2017

First experimental proof of a 70 year old physics theory: First observation of magnetic phase transition in 2-D materials, as predicted by the Nobel winner Onsager in 1943 January 6th, 2017

Investigations of the skyrmion Hall effect reveal surprising results: One step further towards the application of skyrmions in spintronic devices December 28th, 2016

Electron highway inside crystal December 12th, 2016

Chip Technology

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

New TriboLab CMP Provides Cost-Effective Characterization of Chemical Mechanical Wafer Polishing Processes: Bruker Updates Industry-Standard CP-4 Platform for Most Flexible and Reliable Testing June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

Memory Technology

Picosunís ALD solutions enable novel high-speed memories June 27th, 2017

New prospects for universal memory -- high speed of RAM and the capacity of flash: Thin films created at MIPT could be the basis for future development of ReRAM June 17th, 2017

Geoffrey Beach: Drawn to explore magnetism: Materials researcher is working on the magnetic memory of the future April 25th, 2017

New ultrafast flexible and transparent memory devices could herald new era of electronics April 1st, 2017

Discoveries

X-ray photoelectron spectroscopy under real ambient pressure conditions June 28th, 2017

Physicists make quantum leap in understanding life's nanoscale machinery June 27th, 2017

Picosunís ALD solutions enable novel high-speed memories June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Announcements

X-ray photoelectron spectroscopy under real ambient pressure conditions June 28th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosunís ALD solutions enable novel high-speed memories June 27th, 2017

Military

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

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