Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers offer explanation for strange magnetic behavior at semiconductor interfaces

26.08.2013
Discovery could one day lead to electronic materials that provide both computation and data storage

They're not exactly the peanut butter and jelly of semiconductors, but when you put them together, something magical happens.

Alone, neither lanthanum aluminate nor strontium titanate exhibit any particularly notable properties. But when they are layered together, they become not only conductive, but also magnetic.

In the current online edition of Nature Physics, researchers at The Ohio State University report the first-ever theoretical explanation to be offered for this phenomenon since it was discovered in 2004.

Understanding how these two semiconductors interact at their interface could someday lead to a different kind of material—one that provides a single platform for computation and data storage, said Mohit Randeria, co-author of the paper and professor of physics at Ohio State.

"The whole question is, how can you take two materials which do not conduct electricity and do not have magnetic properties, make a sandwich out of them and—lo and behold—at the interface tween them, charge begins to flow and interesting magnetic effects happen?" he said.

"It's like taking two pieces of bread and putting them together and having the sandwich filling magically appear."

By making calculations and modeling the basic physical properties of both materials, Randeria's team has hit upon an explanation for the behavior that seems ironic: the interface between two non-magnetic materials exhibits magnetism.

The team showed how the elemental units of magnetism, called "local moments," are formed at the interface of the two materials. They then showed how these moments interact with the conducting electrons to give rise to a magnetic state in which the moments are arranged in an unusual spiral pattern.

If the physicists' explanation is correct, then perhaps someday, electronic devices could be constructed that exploit the interface between two oxides. Theoretically, such devices would combine the computational abilities of a silicon chip with the magnetic data storage abilities of permanent magnets like iron.

"If you had conduction and magnetism available in the same platform, it could be possible to integrate computer memory with data processing. Maybe different kinds of computation would be possible," Randeria said.

But those applications are a long way off. Right now, the physicists hope that their theoretical explanation for the strange magnetic behavior will enable other researchers to perform experiments and confirm it.

Randeria's coauthors included Ohio State postdoctoral researcher Sumilan Banerjee and former doctoral student Onur Erten, who graduated this summer and is about to begin a postdoctoral fellowship at Rutgers, The State University of New Jersey.

This research was sponsored by the U.S. Department of Energy, the National Science Foundation (NSF), and Ohio State's Center for Emergent Materials, one of a network of Materials Research Science and Engineering Centers funded by NSF.

Contact:

Mohit Randeria
(614) 292-2457
randeria@mps.ohio-state.edu
Written by Pam Frost Gorder
(614) 292-9475
Gorder.1@osu.edu

Pam Frost Gorder | EurekAlert!
Further information:
http://www.osu.edu

More articles from Physics and Astronomy:

nachricht Highest-energy cosmic rays have extragalactic origin
25.09.2017 | CNRS

nachricht NASA'S OSIRIS-REx spacecraft slingshots past Earth
25.09.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

NASA'S OSIRIS-REx spacecraft slingshots past Earth

25.09.2017 | Physics and Astronomy

MRI contrast agent locates and distinguishes aggressive from slow-growing breast cancer

25.09.2017 | Health and Medicine

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>