Researchers discover the existence of elusive spin dynamics in quantum mechanical systems

Researchers from Oak Ridge National Laboratory (ORNL), University of California and Lawrence Berkeley National Laboratory have discovered the existence of elusive spin dynamics in quantum mechanical systems.

The team successfully simulated and measured spins - magnetic particles, which can exhibit a motion known as Kardar-Parisi-Zhang in solid materials at varying temperatures. Up until now, scientists have only found evidence of the spin dynamics in soft matter and other classical materials.

Researchers use unique material to control spin polarization

Researchers used the Advanced Photon Source (APS), a U.S. Department of Energy Office of Science User Facility at DOE’s Argonne National Laboratory, to study ways to manipulate electron spins and develop new materials for spintronics. The research team, led by Chang-Beom Eom at the University of Wisconsin-Madison, designed a new material that has three times the storage density and uses much less power than other spintronics devices.

Not many of these types of materials exist, especially ones that work at room temperature like this one. If the new material can be perfected, it could aid in the creation of more efficient electronic devices with less tendency to overheat. This is particularly important for advancing the development of low-power computing and fast magnetic memory.

Scientists design the smallest cable containing a spin switch

Researchers from the Madrid Institute for Advanced Studies in Nanoscience (IMDEA) and the University of Sevilla have measured for the first time the electrical conductivity of a single carbon nanotube with spin-crosslinked molecules inside it.

Spin-state-dependent electrical conductivity in single-walled carbon nanotubes encapsulating spin-crossover molecules imageIron-based SCO molecules encapsulated in a single carbon nanotube. Credit: Nature Communications

Magnetic molecules could add a new twist to conventional electronics. In particular, spin-crossover (SCO) molecules belong to a family of zero-dimensional (0D) functional units that display a radical spin switch triggered by an electro-structural change activatable by external stimulus such as light, pressure or temperature. The spin switch confers SCO molecules excellent capabilities and functionalities for implementation in nano-electronics. However, their insulating character has so far prevented these molecules from being fully exploited. Several groups have embedded SCO molecules into matrices of conductive materials but the results have not been fully compatible with the requirements of nanoscale devices.

Chiral-induced spin selectivity enables room-temperature spin LEDs

A team of researchers from the National Renewable Energy Laboratory (NREL) and the University of Utah has developed a new type of LEDs that utilizes spintronics without needing a magnetic field, magnetic materials or cryogenic temperatures.

New spin-LED emits a circularly polarized glow image

“The companies that make LEDs or TV and computer displays don’t want to deal with magnetic fields and magnetic materials. It’s heavy and expensive to do it,” said Valy Vardeny, distinguished professor of physics and astronomy at the University of Utah. “Here, chiral molecules are self-assembled into standing arrays, like soldiers, that actively spin polarize the injected electrons, which subsequently lead to circularly polarized light emission. With no magnetic field, expensive ferromagnets and with no need for extremely low temperatures. Those are no-nos for the industry.”

Researchers induce “artificial magnetic texture” in graphene

An international research team, led by the University at Buffalo, has reported an advancement that could help give graphene magnetic properties. The researchers describe in their work how they paired a magnet with graphene, and induced what they describe as “artificial magnetic texture” in the nonmagnetic material. This achievement may, according to the researchers, push forward the spintronics field.

Induced magnetism in graphene could also promote spintronics imageThe image shows eight electrodes around a 20-nanometer-thick magnet (white rectangle) and graphene (white dotted line). Credit: University at Buffalo.

“Independent of each other, graphene and spintronics each possess incredible potential to fundamentally change many aspects of business and society. But if you can blend the two together, the synergistic effects are likely to be something this world hasn’t yet seen,” says lead author Nargess Arabchigavkani, who performed the research as a PhD candidate at UB and is now a postdoctoral research associate at SUNY Polytechnic Institute.

Rice researchers develop theory that could push spintronics forward

A new theory by Rice University scientists could boost the field of spintronics. Materials theorist Boris Yakobson and graduate student Sunny Gupta at Rice’s Brown School of Engineering describe the mechanism behind Rashba splitting, an effect seen in crystal compounds that can influence their electrons’ “up” or “down” spin states, analogous to “on” or “off” in common transistors.

Theory could accelerate push for spintronic devices imageThe left shows the crystal structure of a MoTe2

The Rice model characterizes single layers to predict heteropairs — two-dimensional bilayers — that enable large Rashba splitting. These would make it possible to control the spin of enough electrons to make room-temperature spin transistors, a far more advanced version of common transistors that rely on electric current.

New method that enables transferring materials to any substrate could push forward spintronics and related technologies

Yttrium iron garnet is a material which has special magnetic properties. A new process, developed by physicists at Martin Luther University Halle-Wittenberg (MLU), allows for it to be transferred to any material. The new method could advance the production of smaller, faster and more energy-efficient components for data storage and information processing.

Magnetic materials play a major role in the development of new storage and information technologies. Magnonics is an emerging field of research that studies spin waves in crystalline layers. Spin is a type of intrinsic angular momentum of a particle that generates a magnetic moment. The deflection of the spin can propagate waves in a solid body. "In magnonic components, electrons would not have to move to process information, which means they would consume much less energy," explains Professor Georg Schmidt from the Institute of Physics at MLU. This would also make them smaller and faster than previous technologies.

IMDEA team develops a promising approach to spintronic devices based on low-cost and abundant materials

Some of the latest advances in spintronics are based on nanometric thin film structures with perpendicular magnetic anisotropy in which the spin currents are used to produce changes in the magnetization of a magnetic layer. This effect is known as spin-orbit torque (SOT) and can be enhanced by suitably engineering multilayer stacks composed by alternated magnetic/non-magnetic metals. The typical structures employed to manipulate the magnetization via SOT are multilayers whose basic constituent is a ferromagnetic layer adjacent to heavy metal(s), which confer large spin-orbit coupling and promote the perpendicular magnetic anisotropy. These systems are the basic elements for spin-orbit torque magnetization switching, used in the next generation of magnetoresistive random access memory (MRAM) devices.

The SpinOrbitronics research team, guided by Dr. Paolo Perna at IMDEA Nanociencia, have observed the emergence of an interfacially enabled increase of the spin-orbit torque when an ultrathin Cu interlayer is inserted between Co and Pt in symmetric Pt/Co/Pt trilayer, in which the effective spin-orbit torque is expected to vanish. The enhancement of SOT is accompanied by a reduction of the spin-Hall magnetoresistance, indicating that the spin memory loss effect in the Co/Cu and Cu/Pt interfaces is responsible of both enhanced SOT and reduction in the spin-Hall magnetoresistance.

Quantum computing enables characterization of magnetic materials

A multi-institutional team which included researchers from the Department of Energy's Oak Ridge National Laboratory, the University of Tennessee, Purdue University and D-Wave Systems, succeeded in generating accurate results from materials science simulations on a quantum computer that can be verified with neutron scattering experiments and other practical techniques.

The researchers used the power of quantum annealing, a form of quantum computing, by embedding an existing model into a quantum computer. Their unique approach proved that quantum resources are capable of studying the magnetic structure and properties of materials, which could lead to a better understanding of spin liquids, spin ices and other novel phases of matter useful for data storage and spintronics applications.

Researchers demonstrate the potential of a new quantum material for creating two spintronic technologies

Antiferromagnetic (AFM) spintronics are devices or components for electronics that couple a flowing current of charge to the ordered spin 'texture' of specific materials. The successful development of AFM spintronics could have important implications, as it could lead to the creation of devices or components that surpass Moore's law. But it seems that finding materials with the exact characteristics necessary to fabricate AFM spintronics is highly challenging.

Researchers at the Lawrence Berkeley National Laboratory, UC Berkeley and the National High Magnetic Field Laboratory in Tallahassee have recently identified a new quantum material (Fe1/3 + δNbS2) that could be used to fabricate AFM spintronic devices. In their most recent papers, they demonstrated the feasibility of using this material for two AFM spintronics applications.