February 2009

In magnetic memory devices, information is stored in magnetic elements and typically retrieved by applying a small, external magnetic field. More convenient, however, is the use of a spin-polarized current, in which moving electrons exert a torque on a magnetic element and can switch the direction of its magnetization.

Unfortunately, moving electrons can give rise to electrical noise, which reduces the efficiency of the magnetization control. Now, Yoshichika Otani from the RIKEN Advanced Science Institute in Wako and colleagues have overcome this problem by using a pure spin current*, that is, a diffusion of electron spins without charge motion.

By examining the electronic transport properties of their device, the researchers were able to demonstrate that when the current injected into the first junction is high enough, it creates a spin current high enough to reverse the magnetization at the second junction. Most importantly, the magnetization can be reversed back by applying the same amount of current in the opposite direction.

Via  AZONano

In a genuinely useful piece of spintronics, engineers from European lab CEA, Hitachi, and STMicroelectronics built a 13GHz spin torque RF oscillator based on magnetic tunnelling junctions that is 50x smaller than the equivalent LC oscillator, and tunes over 85% of its frequency compared with 15% for LC types. Measurements over one minute show phase jitter of 36ps_(RMS) with the oscillator set at 7.36GHz. The required stack of magnetic layers has a footprint only 90nm across and is constructed by sputtering.

Via ElectronicsWeekly

Researchers working at the National Institute of Standards and Technology (NIST) have demonstrated for the first time the existence of a key magnetic—as opposed to electronic—property of specially built semiconductor devices. This discovery raises hopes for even smaller and faster gadgets that could result from magnetic data storage in a semiconductor material, which could then quickly process the data through built-in logic circuits controlled by electric fields.

In a new paper, researchers from NIST, Korea University and the University of Notre Dame have confirmed theorists’ hopes that thin magnetic layers of semiconductor material could exhibit a prized property known as antiferromagnetic coupling—in which one layer spontaneously aligns its magnetic pole in the opposite direction as the next magnetic layer. The discovery of antiferromagnetic coupling in metals was the basis of the 2007 Nobel Prize in Physics, but it is only recently that it has become conceivable for semiconductor materials. Semiconductors with magnetic properties would not only be able to process data, but also store it.

We just hear that Atomistix went bankrupt, and QuantumWise has bought all assets. QuantumWise is a start-up born at the Nano-Science Center and the E-Science Center at Copenhagen University in Denmark.

QuantumWise develops software which in particular can be used for research related to future electronic devices such as transistors and memory circuits. This paves the way for computers and storage devices with radically better performance and capacity than today.