Spintronics news and resources

Professor Hideo Ohno from the Laboratory of Nanoelectronics and Spintronics, at Tohoku University is this year's IEEE David Sarnoff Award winner, a very prestigious award. Professor Ohno was in contention for this year's Nobel prize in physics. Here's a 2010 video showing Ohno's group work on integrated circuits using spintronics:

Researchers from the University of South Florida and the University of Kentucky have demonstrated a material in which the spins can be set in a controlled manner. The team suggest using cobalt atoms on a graphene sheet.

The researchers have used state-of-the-art theoretical computations to prove this.

Researchers from Radboud University managed to optically switch individual domains into a definite magnetic state in the insulator Sm1/2Pr1/2FeO3. With short pulses of circularly polarized laser light, they flipped the magnetization of a single magnetic domain within ?5ps.

The team managed to achieve this by taking advantage of the interaction between light of a certain helicity and a spin reorientation transition unique to the material they studied. This is an important step for the complete light control of magnetic domains in a variety of magnets, and highlights an important light-matter interaction in magnets.

Researchers from the Helmholtz Center in Berlin developed a new magnetic valve that can be used for data storage or information processing. The new structure allows an indefinite number of re-write cycles.

The researchers created a defined anisotropy with two thin, stacked ferromagnetic layers: they wanted to create a structure in which a magnetic characteristic within the material changes in a well defined way. They added a third non-magnetic layer (made of Tantalum) between the two layers, which made the whole structure behave like a spin valve.

Researchers at the Max Planck Institute of Microstructure Physics in Halle developed a new switching mechanism for magnetic current. The idea is to use a short electric pulse to change the magnetic transport properties of a material sandwich consisting of a ferroelectric layer between two ferromagnetic materials. The new mechanism could be used to store information in four states of a storage point, not just two - which doubles storage density or lowers the size of MRAM devices.

In ferroelectric materials, voltage switches between the two directions of an electric polarisation – depending on its polarity – not unlike when a magnetic field permanently reverses the polarity of a ferromagnet. As ions shift within the material structure during this process, the polarisation remains intact, even after the voltage has been reduced. It is possible, however, to reverse the switch again with a similarly large voltage with reversed polarity.

Researchers with the U.S. DOE's Berkeley Lab in collaboration with scientist from University of Notre Dame have determined the origin of the charge-carriers responsible for the ferromagnetic properties that make gallium manganese arsenide such a hot commodity for spintronic devices.

The study showed that the holes (positively-charged energy spaces) in gallium manganese arsenide that control the Curie temperature, the temperature at which magnetism is lost, are located in an impurity energy band rather than a valence energy band, as many scientists have argued. This finding opens the possibility of fabricating gallium manganese arsenide so as to expand the width and occupation of the impurity band and thereby boost the Curie temperature to improve spintronic potential.

Here's an nice video introducing the NSF Center for Molecular Spintronics at North Carolina State University:

Researchers have discovered a new wide class of topological insulators (materials that are insulators in the bulk but conductors at the surface) that have very promising properties. These new TIs may enable tuning both electronic and spin (that is, magnetic) properties by using different compounds and confirms the possibility to grow topological insulators with deep-laying, self-protecting and, thus, technologically relevant conducting states. This may have applications in spintronics and quantum computation.

Ron Jansen from the Spintronics Research Center at the National Institute for Advanced Industrial Science and Technology (AIST) gives an interesting lecture about recent progress in silicon spintronics:

Researcher Michel de Jong of the NanoElectronics group (MESA+) in the University of Twente (Netherlands) received a €1.5 million grant from the European Research Council to fund his Spintronics work (this is his second ERC grant). Michel de Jong is focusing on organic materials, in particular in Buckyballs (spherical C60 molecules held together by weak bonds) sandwiched between two magnetic materials.

Michel explains that these molecules have very little effect on electron spin, which is a great advantage as it enables them to store spin information for much longer periods of time than silicon. Buckyballs have also been used to create Graphene Quantum Dots.