Topological insulators can be used to create "spin batteries"

Apr 20, 2017

Researchers from Purdue University have demonstrated how topological insulators can be used to create rechargeable "spin batteries". The demonstration showed how spin momentum locking can retain the spin even after two days without current.

Persistent spin polarization measurement

Spin momentum locking is an effect in topological insulators in which the spin of the electrons on the edge of the material change their spin when current is applied.

Researchers achieve magnetic switching using domain wall displacement

Apr 17, 2017

Researchers from Helmholtz-Zentrum Berlin managed to develop a robust and reliable magnetization switching process using domain wall displacement - without any applied field. This could lead to highly efficient spintronics memory devices.

Magnetic switching by domain wall displacement (HZB photo)

A spintronics memory design that uses tiny rings to enable two stable magnetization states - but the switching of the states usually requires a circular magnetic field. The researchers now devised a way to overcome to requirement - by using slightly displaced holes in the rings (which are thus thinner on one side), which means that a short uniaxial magnetic field pulse can switch between the two possible vortex states.

Researchers develop a spin-resolved oscilloscope

Mar 14, 2017

Researchers from the Tokyo Institute of Technology and Nippon Telegraph and Telephone Corporation developed a measurement instrument for plasmonics and spintronics. The so-called "spin-resolved oscilloscope" is seen as a step towards future "spin-plasmonics" devices that can achieve ultra-high-speed and low-energy-consumption.

Spin resolved oscilloscope scheme (TIT 2017)

The spin-resolved oscilloscope is composed of a spin filter and nanometer-scale time-resolved charge detectors. The spin filter separates the spin-up and -down electrons, while the time-resolved charge detector measures the waveforms of the charge-density waves. By combining these spintronic and plasmonic devices, the spin-resolved oscilloscope is established. The new device enables the measurement of the waveforms of both charge and spin signals in electronic devices. The charge signal is the total charge of the spin-up and -down electron densities, while the spin signal is the difference between the spin-up and -down electron densities.

Researchers develop world's fastest magnetic tunnel junction that is switched by light pulses

Mar 12, 2017

Researchers from the University of Minnesota developed a magnetic tunnel junction that is switched by using a short pulse of light. The switch operation takes only one trillionth of a second - which makes this the world's fastest magnetic tunnel junction.

Magnetic tunnel junction light-switch photo

To create this device, the researchers used ITO to create a transparent electrode on top of an ally made from called gadolinium, iron and cobalt. This material is already known to be switchable using light pulses.

Spin-LED enable almost purely circularly polarized emission

Feb 10, 2017

Researchers from the Tokyo Institute of Technology managed to achieve an almost purely circularly polarized (CP) electroluminescence (EL) in spin-polarized LEDs at room temperature without an external magnetic field.

Spin-LED design and images (Tokyo Institute of Technology)

The researchers used LEDs and a polycrystalline Fe in-plane spin injector. During the experiment the researchers injected spins of a given type, which were dispersed due to spin relaxation. Radiative recombination subsequently occurred, which was observed in the form of a linearly polarized emission. Almost pure circularly polarized emission was achieved when the current density was high enough.