Research / Technical - Page 18

Researchers from Japan's National Institute for Materials Science (NIMS) have managed to introduce a quantum well structure into a conventional magnetic tunnel junction (MTJ). The researchers say that the QW structure can enhance the tunneling magnetoresistance (TMR) ratio by spin-dependent resonant tunnel (SDRT) effect, with a value of 1.5 times comparing with no SDRT case, at room temperature.

The researchers tell us that the key point of the QW formation is the band mismatch between Cr and Fe for majority band, and the mismatch-free Fe/MgAl₂O₄ interface. The finding is not just useful for enhancement of TMR ratio, it also provides a benefit that the TMR ratio could be kept almost constant in a wide bias voltage range of from -1V to 0.5V.

Researchers from the University of Groningen developed a two-dimensional spin transistor, in which spin currents were generated by an electric current through graphene. The device also include a monolayer transition metal dichalcogenide (TMD) that is placed on the graphene to induce charge-to-spin conversion.

Graphene is an excellent spin transporter, but spin-orbit coupling is required to create or manipulate spins. The interaction is weak in the graphene carbon atoms, but now the researchers have shown that adding the TMD layer increases the spin-orbit coupling.

Researchers from Spain's ICN2, in collaboration with Imec and K.U. Leuven have developed a modified graphene-based nanodevice fabrication technique that can increase the spin lifetime and relaxation length by up to three times.

The researchers used CVD-made graphene grown on a platinum foil. By optimizing several standard processes, the researchers managed to reduce the impurity level of the graphene.

Researchers from two FLEET universities in Australia, RMIT and UNSW, collaborated in a theoretical–experimental project that discovered a previously unseen mode of giant magneto-resistance (GMR) in 2D Fe₃GeTe₂ (FGT). This surprising result suggests a different underlying physical mechanisms in vdW hetero-structures.

The research shows that vdW materials (2D material) could offer higher functionality compared to traditional spintronic approaches.

Researchers from the University of Tokyo have developed a spintronics device that can quickly and efficiently magnetize - which they say is between one and two orders of magnitude more power efficient than current spintronics device.

The researchers used a ferromagnetic semiconductor material called gallium manganese arsenide (GaMnAs) - the magnetization of which can be fully reversed with the application of very small current densities.

Researchers RIKEN in collaboration with several other Universities, developed an organic solid-state spin filtering device. The device is based on a thin layer of artificial molecular motors.

The researcher explain that the artificial molecular motors demonstrate four times chirality inversion by light irradiation and thermal treatments during the 360-degree molecular rotation. This means that the spin-polarization direction of electrons that pass through the molecular motors are switched by light irradiation or thermal treatments.

Researchers from the University of Glasgow together with European partners developed a new method to transfer spin information between layers of spintronic materials - basically enabling the development of 3D magnetic structures.

This discovery is based on chiral spin interaction. The researchers were able to stablize these interactions within a magnetic layer and, for the first time, extend these types of interactions to other layers.

Researchers from the Moscow Institute of Physics and Technology, in collaboration with researchers from Germany and the Netherlands have developed a new memory technology they call optically-assisted MRAM which is based on changing the spin state via THz pulses.

The researchers say that the new technique is extremely efficient (the power required to switch a "bit" will be a thousand times smaller compared to current MRAM devices) and fast.

Researchers from the University of Texas at San Antonio (UTSA) have developed a graphene-based "zero-power" interconnect that can present the loss of spin in Spintronics devices.

In the new architecture, the graphene nanomaterials are used as both the spin transport channel and the tunnel barrier. The researchers use reduced graphene oxide in a single-layer configuration. The researchers discovered that by controlling the amount of oxide on the graphene layers, the tune electrons’ conductivity can be fine-tuned.

Researchers from Shinshu University, the Chinese University of Hong Kong, the University of Tokyo, Tsinghua University, Kyoto University and Nanyang Technological University have experimentally demonstrated a breakthrough in manipulation of skyrmions using only electric field.

The team, led by Professor Xiaoxi Liu of Shinshu University, designed and fabricated magnetic multilayer films in the form of racetracks where the thickness of the films had a slope. They demonstrated that many skyrmion bubbles can be created and directionally displaced about 10 micrometres by applying a voltage as low as 9 volt in a repeatable manner. They also found that the domain wall displacement and velocity induced by the variation of electric field are proportional to the absolute value of voltage.