Research / Technical - Page 17

Researchers from the University of Arizona discovered that in common Magnetic Tunnel Junctions (MTJ), there's a thin (2D) layer of Iron Oxide. This layer was found to act as a contaminant which lowers the performance achieved by MTJs.

This Iron Oxide layer, however, can also be seen as a blessing - the researchers discovered that the layer behaves as a so-called antiferromagnet at extremely cold temperatures (below -245 degrees Celsius). Antiferromagnets are promising as these can be manipulated at Terahertz frequencies, about 1,000 times faster than existing, silicon-based technology. This is the first research that shows how Antiferromagnets can be controlled as part of MTJs.

Researchers from Aarhus University in Denmark received a EUR 4.4 million grant from the EU FET to develop novel spintronics-based AI hardware. The researcher say that their suggested design can end up having 100,000 times the performance of the state-of-the-art AI systems of today.

The project, called SpinAge, will revolve around a neuromorphic computer system (NCS) design that is unique, scalable and highly energy efficient (the researchers estimate that the new design will be more efficient than current designs by at least a factor of 100). The synaptic neurons in this system will be based on spintronics technology.

Researchers from the National University of Singapore (NUS) have identified a promising spintronics candidate material - few-layer thin semimetal molybdenum ditelluride (MoTe₂).

Semimetals feature material properties that are between metals and semiconductors. The researchers found that an extremely thin (few-layers, almost 2D) MoTe₂ features an intrinsic Spin Hall Effect (SHE).

Dr. Wei Zhang, an assistant professor of physics at Oakland University, has earned the National Science Foundation’s Faculty Early Career Development Program Award and a $500,000 grant over five years to study quantum spintronics.

Quantum spintronics, a relatively new field, studies how a material’s quantum properties (either natural or engineered) could be used to advance future spintronics devices. The grant funding will help facilitate the development of new quantum spintronic laboratory modules at the university, as well as outreach and education activities.

Researchers from the Tokyo Institute of Technology (Tokyo Tech) developed a new MRAM cell structure that relies on unidirectional spin Hall magnetoresistance (USMR). The new cell structure is reportedly very simple with only two layers which could lead to lower-cost MRAM devices.

The spin Hall effect leads to the accumulation of electrons with a certain spin on the lateral sides of a material. By combining a topological insulator with a ferromagnetic semiconductor, the researchers managed to create a device with giant USMR.

Researchers from Kiel University and European colleagues designed and fabricated single molecular spin switches. The newly developed molecules feature stable spin states and do not lose their functionality upon adsorption on surfaces.

The researchers say that the spin states of the new compounds are stable for at least several days. The new molecules have three properties that are coupled with each other in such a feedback loop: their shape (planar or flat), the proximity of two subunits, called coordination (yes or no), and the spin state (high-spin or low-spin). Thus, the molecules are locked either in one or the other state. Upon sublimation and deposition on a silver surface, the switches self-assemble into highly ordered arrays. Each molecule in such an array can be separately addressed with a scanning tunneling microscope and switched between the states by applying a positive or negative voltage.

Researchers from the NREL and the University of Utah have demonstrated how electron transport with a particular spin state through a two-dimensional hybrid organic-inorganic perovskite can be manipulated by introducing special organic molecules in the multilayer structure.

One way to control spin-polarized currents is through "chiral-induced" spin selectivity where the transport of electrons depends upon the transporting materials’ chirality—a structural property of a system where its mirror image is not superimposable on itself. The scientists have demonstrated how to integrate a chiral organic sublattice into an inorganic framework, creating a chiral system that can transport electrons with the desired spin control. In such systems, the chiral perovskite films act as a spin filter.

Researchers from Spain's ICN2 institute have used numerical simulations to show that spin diffusion length in graphene is independent of grain size. The researchers base their calculations on CVD grown graphene. CVD methods produces high quality materials that are built from several single-crystal sheets separated from one another through grain boundaries.

The research have shown that the grain boundaries do not have any effect on the spin transport. The researchers considered two different mechanisms for spin relaxation - randomization of spins within the grains due to spin-orbit coupling, and scattering in a grain boundary. The main implication of this research is that single-domain graphene may not be a requirement for spintronics applications.

An international team of researchers from France and Sweden designed a new concept of an energy harvesting engine based on spintronics and quantum thermodynamics. The basic idea is to use electron spin to harvest thermal fluctuations at room temperature.

The researchers make use of the fact that paramagnetic centers, or atom-level magnets, fluctuate their spin orientation due to heat. In the so called spin-engine, the a spontaneous bias voltage V appears between the electrodes, and thus a spontaneous current flows once the electrical circuit is closed.

There are still many challenges to create such devices (the team made some initial experiments) - but the researchers say that this concept could create chips that continuously produce electrical power with a power density that is 3x greater than raw solar irradiation on Earth.

Researchers from the University of Groningen created curved spin transport channels. The researchers discovered that this new geometry makes it possible to independently tune charge and spin currents.

Most spintronics devices to date were made from flat surfaces, and this research focused on spin currents behaviors in curved channels. The scientists say that the new research enables the efficient integration of spin injectors and detectors or spin transistors into modern 3D circuitry.