Home > Press > Spintronics development gets boost with new findings into ferromagnetism in Mn-doped GaAs
![]() |
Fig.1: Crystal structure of (Ga,Mn)As. Mn ions substituted for Ga have a magnetic moment, and the magnetic moment of each Mn ion aligns along the same direction when (Ga,Mn)As becomes a ferromagnet. CREDIT: Seigo Souma |
Abstract:
A research group at Tohoku University's WPI-AIMR has succeeded in finding the origin and the mechanism of ferromagnetism in Mn-doped GaAs. The discovery is significant as it will accelerate the development of the spintronic element.
GaAs, like silicon, is a well-known semiconductor commonly used in high-speed electronic devices and laser diodes.
When manganese (Mn) atoms are doped into a GaAs crystal ((Ga,Mn)As), the crystal exhibits characteristics and properties of both the semiconductor and magnet (Fig. 1). Since it is possible to use an electric field to control the magnetism in (Ga,Mn)As, Mn-doped GaAs has been a key material in spintronic devices and a significant contributor to the development of spintronics technology.
However, although it has been 20 years since that discovery, the mechanism of ferromagnetism in (Ga,Mn)As is still not widely understood or well explained. There remains fierce debate and confusion, leading to obstacles preventing the progress and further development of spintronics technology.
The researchers at Tohoku University, led by Profs. H. Ohno and T. Takahashi, have succeeded in directly observing the electronic states which participate in creating the ferromagnetism by photoemission spectroscopy. They found that doped Mn atoms extract electrons from As atoms, leaving "holes" (empty states of electrons) in the As orbital. This then causes the ferromagnetism in (Ga,Mn)As (seen in Fig. 2).
"This finding resolves the long-standing problem in the mechanism of ferromagnetism in (Ga,Mn)As," says researcher Seigo Souma. "It also accelerates the materials engineering of magnetic semiconductors, as well as the tunable controlling of spin states in spintronic devices. This is very significant result and we're excited about the potential it represents."
####
About Tohoku University
The Advanced Institute for Materials Research (AIMR) at Tohoku University is one of nine World Premier International Research Center Initiative (WPI) Programs established with the support of the Japanese government. It aims to develop world-class research bases in Japan. Since its establishment in 2007, AIMR has been active in conducting research activities and creating new systems in order to become a global center for materials science. In recent years, AIMR has also been conducting fundamental research by finding connections between materials science and mathematics.
For more information, please click here
Contacts:
Seigo Souma
Copyright © Tohoku 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.
Related Links |
Related News Press |
Physics
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
News and information
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
Magnetism/Magnons
Magnetism in new exotic material opens the way for robust quantum computers June 4th, 2025
Possible Futures
Ben-Gurion University of the Negev researchers several steps closer to harnessing patient's own T-cells to fight off cancer June 6th, 2025
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Spintronics
Quantum materials: Electron spin measured for the first time June 9th, 2023
Chip Technology
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Programmable electron-induced color router array May 14th, 2025
Enhancing power factor of p- and n-type single-walled carbon nanotubes April 25th, 2025
Ultrafast plasmon-enhanced magnetic bit switching at the nanoscale April 25th, 2025
Quantum Computing
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
Magnetism in new exotic material opens the way for robust quantum computers June 4th, 2025
Programmable electron-induced color router array May 14th, 2025
Discoveries
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Materials/Metamaterials/Magnetoresistance
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025
Announcements
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
![]() |
||
![]() |
||
The latest news from around the world, FREE | ||
![]() |
![]() |
||
Premium Products | ||
![]() |
||
Only the news you want to read!
Learn More |
||
![]() |
||
Full-service, expert consulting
Learn More |
||
![]() |