April 2009

Researchers have developed a new technique to flip the spin of unpaired electons - Ballistic Spin Resonance.

Previous methods to do this - Electron Spin Resonance using high-frequency electric fields is difficult to generate on a chip. The new method should make it easier. The major drawback of the new method - the electrons are flipped in a random way... you can't actually choose the spin. Future studies hope to overcome this.

Read more at NanoWerk

Researchers from the Queen Mary University of London and Switzerland-based Paul Scherrer Institute have succeeded to measure how magnetic polarisation is lost. The resulting improved understanding of the workings of electronic devices using the spin degree of freedom, and the field of organic spintronics in general, finally paves the way for ensuring higher efficiencies in spin transfer, and thus for the future of spin-based electronic devices.

The researchers came out with a new depth-resolved technique for measuring the spin polarisation of current-injected electrons in an organic spin valve and found that the temperature dependence of the measured spin diffusion length was correlated to the device’s magneto-resistance. The scientists used elementary particles called muons that act as tiny magnets, to measure the magnetic field within the device.

Spin valves are usually made up of at least three layers – two magnetic layers separated by a non-magnetic one – and the team attempted to investigate how spins travel across the middle of these layers. It is believed that the research team’s findings are quite significant both to the understanding of spintronic devices, and to the eventual development of next generation data storage solutions and other novel devices and applications.

NVE Corporation today announced the introduction of the AAT001-10E TMR Angle Sensor, NVE's first commercial sensor to use Tunneling Magnetoresistance (TMR), which produces an even more giant signal than Giant Magnetoresistance.

Also known as Spin-Dependent Tunneling (SDT), Magnetic Tunnel Junction (MTJ), or Tunneling Magnetic Junction (TMJ), Tunneling Magnetoresistance is a spintronic quantum effect that produces a dramatic resistance change in a normally insulating layer, depending on the magnetic field and thus the predominant electron spin in a free layer. The new device has four TMR elements configured as an angle sensor with full quadrature sine and cosine outputs.

The parts come in an ultraminiature 2.5 millimeter by 2.5 millimeter six-pin TDFN package. In typical operation, an external bar or split-pole magnet provides a saturating magnetic field of 30 to 200 Oersteds in the plane of the sensor.

TMR produces a very large signal with no amplification for exceptional precision, wide air-gap tolerance, and low power consumption due to high element resistance. The AAT001-10E is ideal for applications such as rotary encoders, automotive rotary sensors, motor shaft position sensors, and knob position sensors.

Available now, AAT001-10E angle sensors are priced at $1.94 each in 1,000-piece quantities. Split-pole ferrite magnets for use with the sensors are available and priced at $1.15 each in 1,000-piece quantities. Customers can also use their own magnets.