Fullerene used to preserve electron spin over long distances

Researchers from Tohoku University have shown that electron spins can be preserved for long distances using optimized organic compounds. This is because organic compounds are made mostly from carbon, in which the spin–orbit interaction is quite small. Using fullerene (C60) films the researchers made devices in which electrons traveled up to 110 nm at room temperature while preserving their spin.

The researchers used fullerence because there's no hydrogen in it (common in other organic materials) and this helps reduce the hyper fine interactions between electron and nuclear spins that can induce spin-flipping events. They built an organic spin valve in which two ferromagnetic electrons are placed in contact with an organic layer.

A new spin amplifier can be used at room temperatures

Researchers from Sweden, Germany and the US managed to develop an effective spin amplifier based on a non-magnetic semiconductor - that works at room temperature. The amplification occurs through deliberate defects in the form of extra gallium atoms introduced into an alloy of gallium, indium, nitrogen and arsenic.

Such a device can be used along a path of spin transport to amplify signals that have weakened along the way. By combining this with a spin detector, it may be possible to read even extremely weak spin signals.

New plastic-based spintronics magnetic field sensor developed, is "dirt cheap"

Researchers from the University of Utah developed a Spintronics organic thin-film transistor that can be used as a cheap magnetic field sensor that never needs to be calibrated and is capable of detecting intermediate to strong magnetic fields. The film also resists heat and degradation and operates at room temperatures.

The thin film is an organic semiconductor polymer called MEH-PPV - a very cheap material. In fact the researchers say that this new sensor is "dirt cheap" - it costs just as little as a drop of regular paint. The researchers are thinking about launching a spin-off company to commercialize this technology.

Electric ferromagnetism at room temperature shown in cobalt-doped titanium dioxide

Researchers from Japan managed to induce and control magnetization in a ferromagnetic semiconductor (cobalt-doped titanium dioxide) at room temperature. This is another step towards room-temperature Spintronics.

The researchers constructed an electric double-layer transistor structure (see above) which uses a liquid electrolyte as a gate insulator, in which a small applied voltage is sufficient to generate a very high electric field.

Barium Titanate exhibits a multiferroic property at room temperature

A new study managed to see the showed that barium titanate (BaTiO3) exhibits a multiferroic property (dual traits of both ferroelectric and ferromagnetic) at room temperature using soft X-ray resonant magnetic scattering. The EU-funded project was led by researchers from Germany, France and the United Kingdom.

This unique property of BaTiO3 could be used to make spintronic devices - quickly and cost effectively. The EU's ELISA (European light sources activities - synchrotrons and free electron lasers) project granted 10 million euro to the project, and the FEMMES (FerroElectric Multifunctional tunnel junctions for MEmristors and Spintronics) project contributed a further 2 million euro.

Electron spin-splitting (Rashba effect) shown in Bismuth selenide

Electron spin-splitting effect (Rashba effect) was demonstrated in a semiconductor (Bismuth selenide) that is far larger than has ever been seen before. This could lead the way towards room-temperature spintronic devices. The Rashba effect is the phenomenon of spin splitting with an applied electric field instead of a magnetic field.

The Rashba effect is crucial for spintronic devices: for example when designing spin transistors, electrons of a single spin are injected and then – under an applied electric field – have their spins rotated. Rashba effect in well-established semiconductors (silicon or gallium arsenide for example) is very small - and so electrons have to travel large distances before any spin rotation is noticeable. This requires very pure materials and very low temperatures.

Researchers report a breakthrough in the use of diamond in quantum physics

Researchers from the University of California, Santa Barbara and the University of Konstanz in Germany, led by David Awschalom reported a breakthrough in the use of diamond in quantum physics. The physicists were able to coax the fragile quantum information contained within a single electron in diamond to move into an adjacent single nitrogen nucleus, and then back again using on-chip wiring.

The discovery shows the high-fidelity operation of a quantum mechanical gate at the atomic level, enabling the transfer of full quantum information to and from one electron spin and a single nuclear spin at room temperature. The process is scalable, and opens the door to new solid-state quantum device development.

Dilute ferromagnetic oxide materials can be used in spintronic devices

Researchers from Japan discovered that dilute ferromagnetic oxide materials remain in a ferromagnetic state at room temperature. The team used cobalt-doped titanium dioxide (Co:TiO2) as their study material. This means hat magnetism and conductivity are correlated in thin films of Co:TiO2. Such materials may plan an important role in spintronic devices (MRAM or spin transistors).

Researchers from the University of Utah develop new room-temperature Spintronic transistors

Researchers from the University of Utah developed a new spintronic transistor that can be used to align electron spin for a record period of time in silicon chips at room temperature. The research was funded by the National Science Foundation.

The researchers used electricity and magnetic fields to inject "spin polarized carriers" - namely, electrons with their spins aligned either all up or all down - into silicon at room temperature. The new technique was to use magnesium oxide as a "tunnel barrier" to get the aligned electron spins to travel from one nickel-iron electrode through the silicon semiconductor to another nickel-iron electrode. Without the magnesium oxide, the spins would get randomized almost immediately, half up and half down.

Spin Ratchets - a new electronic structure for generating spin current

Researchers from the Institut Català de Nanotecnologia (ICN), in Barcelona have demonstrated a new device that induces electron spin motion without net electric current. They call this device a 'ratchet', in analogy to a ratchet wrench which provides uniform rotation from oscillatory motion. The Spin Ratchets achieve directed spin transport in one direction, in the presence of an oscillating signal. Most important, this signal could be an oscillatory current that results from environmental charge noise; thus future devices based on this concept could function by gathering energy from the environment.

The ratchet efficiency can be very high - reported results show electron polarizations of the order of 50%, but they could easily exceed 90% with device design improvements. The spin ratchet, which relies on a single electron transistor with a superconducting island and normal metal leads, is able to discriminate the electron spin, one electron at a time. The devices can also function in a “diode” regime that resolves spin with nearly 100% efficacy and, given that they work at the single-electron level, they could be utilized to address fundamental questions of quantum mechanics in the solid state or to help prepare the path for ultrapowerful quantum or spin computers.