Featured Research

from universities, journals, and other organizations

Quantum tricks drive magnetic switching into the fast lane

Date:
April 3, 2013
Source:
DOE/Ames Laboratory
Summary:
Researchers in the U.S. and Greece have found a new way to switch magnetism that is at least 1000 times faster than currently used in magnetic memory technologies. Magnetic switching is used to encode information in hard drives, RAM and other computing devices.

Magnetic structure in a colossal magneto-resistive manganite is switched from antiferromagnetic to ferromagnetic ordering during about 100 femtosecond (10-15 s) laser pulse photo-excitation. With time so short and the laser pulses still interacting with magnetic moments, the magnetic switching is driven quantum mechanically -- not thermally. This potentially opens the door to terahertz (1012 hertz) and faster memory writing/reading speeds.
Credit: Image courtesy of DOE/Ames Laboratory

Researchers at the U.S. Department of Energy's Ames Laboratory, Iowa State University, and the University of Crete in Greece have found a new way to switch magnetism that is at least 1000 times faster than currently used in magnetic memory technologies. Magnetic switching is used to encode information in hard drives, magnetic random access memory and other computing devices.

Related Articles


The discovery, reported in the April 4 issue of Nature, potentially opens the door to terahertz (1012 hertz) and faster memory speeds.

Ames Laboratory physicist Jigang Wang and his team used short laser pulses to create ultra-fast changes in the magnetic structure, within quadrillionths of a second (femtosecond), from anti-ferromagnetic to ferromagnetic ordering in colossal magnetoresistive materials, which are promising for use in next-generation memory and logic devices. Scientists, led by Ilias E. Perakis, at the University of Crete developed the theory to explain the observation.

So, some scientists have turned their attention to colossal magnetoresistive (CMR) materials because they are highly responsive to the external magnetic fields used to write data into memory, but do not require heat to trigger magnetic switching.

"Colossal magnetoresistive materials are very appealing for use in technologies, but we still need to understand more about how they work," said Wang. "And, in particular, we must understand what happens during the very short periods of time when heating is not significant and the laser pulses are still interacting with magnetic moments in CMR materials. That means we must describe the process and control magnetism using quantum mechanics. We called this 'quantum femto-magnetism.'"

Wang's team specializes in using ultra-fast spectroscopy, which Wang likens to high-speed strobe photography, because both use an external pump of energy to trigger a quick snapshot that can be then re-played afterwards. In ultra-fast laser spectroscopy, a short pulse of laser light is used to excite a material and trigger a measurement all on the order of femtoseconds.

"In one CMR manganite material, the magnetic order is switched during the 100-femtosecond-long laser pulse. This means that switching occurs by manipulating spin and charge quantum mechanically," said Wang. "In the experiments, the second laser pulse 'saw' a huge photo-induced magnetization with an excitation threshold behavior developing immediately after the first pump pulse."

The fast switching speed and huge magnetization that Wang observed meet both requirements for applying CMR materials in ultra-fast, terahertz magnetic memory and logic devices.

"Our strategy is to use all-optical quantum methods to achieve magnetic switching and control magnetism. This lays the groundwork for seeking the ultimate switching speed and capabilities of CMR materials, a question that underlies the entire field of spin-electronics," said Wang. "And our hope is that this means someday we will be able to create devices that can read and write information faster than ever before, yet with less power consumed."

Tianqi Li, Aaron Patz, Jiaqiang Yan and Thomas Lograsso collaborated on the experimental work at Ames Laboratory and Iowa State University. Leonidas Mouchliadis at the University of Crete and the Institute of Electronic Structure and Laser at the Foundation for Research and Technology -- Hellas in Greece helped develop the theory used to interpret the experiments.


Story Source:

The above story is based on materials provided by DOE/Ames Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tianqi Li, Aaron Patz, Leonidas Mouchliadis, Jiaqiang Yan, Thomas A. Lograsso, Ilias E. Perakis, Jigang Wang. Femtosecond switching of magnetism via strongly correlated spin–charge quantum excitations. Nature, 2013; 496 (7443): 69 DOI: 10.1038/nature11934

Cite This Page:

DOE/Ames Laboratory. "Quantum tricks drive magnetic switching into the fast lane." ScienceDaily. ScienceDaily, 3 April 2013. <www.sciencedaily.com/releases/2013/04/130403200312.htm>.
DOE/Ames Laboratory. (2013, April 3). Quantum tricks drive magnetic switching into the fast lane. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2013/04/130403200312.htm
DOE/Ames Laboratory. "Quantum tricks drive magnetic switching into the fast lane." ScienceDaily. www.sciencedaily.com/releases/2013/04/130403200312.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins