spintronics tagged posts

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

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...

The illustration depicts the characteristic spin orientation (arrows) of electrons in a topological insulator (below). Using an initial circular polarised laser pulse, the spins are excited and point up or down. This can be proven by a second linearly polarised laser pulse (above). Credit: HZB

Scientists have shown how spin-polarized currents can be initiated in a controlled manner within samples of topological insulator material. In addition, they were able to manipulate the orientation of the spins of these currents. They thereby demonstrated that this class of materials is suitable for data processing based on spin.

Future information technologies should employ considerably less energy for processing data via topological insulators (with electrons at the surface being extremely mobile, ...

This is a schematic illustration of the lattice and magnetic structures for EuMnBi2 at zero field, together with the formal valence of each ion. The arrangement of the Mn sublattice is assumed to be the same as in SrMnBi2. Credit: Hideaki Sakai

This achievement will lead to a new field of study, strong correlated quantum transport of Dirac electrons, and become an innovation in realizing super high speed spintronics, the foundation of high-speed and energy-saving electronics.

A/Prof Hideaki Sakai at Osaka University and A/Prof Shintaro Ishiwata, Hidetoshi MASUDA (Grad Student) at Uni of Tokyo succeeded in the synthesis of high-quality single crystals of EuMnBi2, a layered compound which is thought to have both properties of Dirac fermions and magnets, using flux growth in a high vacuum...

This illustration shows the flow of a magnetic property of electrons known as spin current from a magnetic material (blue), to a nonmagnetic material (red). Credit: SLAC National Accelerator Laboratory

The result, which revealed a surprising loss of current along the way, is an important step toward realizing next-gen “Spintronics”. Spin current is an inherent magnetic property common to all electrons – as it travels across materials. Modern computing relies on the precise control of electric charges that zip around from component to component in labyrinth-like channels in semiconductors. Spintronics could change that by tapping electrons’ spin, with “up” or “down” orientation, rather than their charge.

Finding a way to directly control this up or down property would rule out the need to f...