Researchers develop conducting system that controls the spin of electrons and transmits a spin current over long distances

In a new study by a team of Duke University and Weizmann Institute researchers, led by Michael Therien, professor of chemistry at Duke, a new achievement was reported: The development of a conducting system that controls the spin of electrons and transmits a spin current over long distances, without the need for the ultra-cold temperatures required by typical spin-conductors.

"The structures we present here are exciting because they define new strategies to generate large magnitude spin currents at room temperature," said Chih-Hung Ko, first author of the paper and recent Duke chemistry Ph.D.

Read the full story Posted: Feb 02,2022

Researchers detect thermal-magnetic flow with a diamond-based quantum sensor

Researchers from Japan Advanced Institute of Science and Technology (JAIST), Kyoto University and the National Institute for Materials Science in Japan have detected energetic magnons in yttrium iron garnet (YIG), a magnetic insulator, by using a quantum sensor based on diamond with NV centers.

Nitrogen-vacancy (N-V) centers in diamond, basically a point defect consisting of a nitrogen atom paired with an adjacent lattice vacancy, have emerged as a key for high-resolution quantum sensors. It has been demonstrated that N-V centers can detect coherent magnon. However, detecting the thermally excited magnons by heat using N-V centers is difficult since the thermal magnons have much higher energy than the spin state of N-V centers, limiting their interaction.

Read the full story Posted: Jan 30,2022

Multi-functional “quantum detergent” for spintronic applications

An international team of researchers, led by the National Research Council (CNR), IOM institute in Trieste, Italy, and the Departments of Chemistry at Princeton University, Louisiana State University and Rutgers University in United States, has relied in a joint venture between theorists, experimentalists and sample growers across chemistry and physics to study the magnetic and electronic properties of EuSn2P2, a magnetic topological insulator composed of Europium, Tin, and Phosphorus arranged in a layer-by-layer crystalline structure.

The understanding and the interplay of magnetism and high-order topology in a quantum material is one of the most challenging research directions in materials science, holding potentialities for future spintronics applications, where the spin carried by an electron, being an essential quantum entity, could be manipulated and used as information carrier in a device and/or as a single quantum bit of information.

Read the full story Posted: Jan 23,2022

Spin-orbit–driven ferromagnetism detected in 'magic-angle' twisted bilayer graphene

A research team from Brown University has found a surprising new phenomenon that can arise in 'magic-angle graphene' - two sheets of graphene that are stacked together at a particular angle with respect to each other, giving rise to various fascinating behaviors. In a recent research, the team showed that by inducing a phenomenon known as spin-orbit coupling, magic-angle graphene becomes a powerful ferromagnet.

"Magnetism and superconductivity are usually at opposite ends of the spectrum in condensed matter physics, and it's rare for them to appear in the same material platform," said Jia Li, an assistant professor of physics at Brown and senior author of the research. "Yet we've shown that we can create magnetism in a system that originally hosts superconductivity. This gives us a new way to study the interplay between superconductivity and magnetism, and provides exciting new possibilities for quantum science research."

Read the full story Posted: Jan 09,2022

Novel semiconductor sheds new light on Anomalous Hall Effect

Researchers at Tokyo Institute of Technology, the University of Tokyo, Japan Science and Technology Agency (JST), RIKEN and Comprehensive Research Organization for Science and Society (CROSS) have demonstrated a large, unconventional anomalous Hall resistance in a new magnetic semiconductor in the absence of large-scale magnetic ordering.

This validates a recent theoretical prediction and provides new insights into the anomalous Hall effect, a quantum phenomenon that has previously been associated with long-range magnetic order.

Read the full story Posted: Jan 02,2022

Researchers succeed in measuring the properties of spin waves in graphene

Researchers from Harvard University and Japan's National Institute for Materials Science have demonstrated a new way to measure the properties of spin waves in graphene.

New method to measure spin waves in graphene imageA charge sensor measuring the cost of electrons surfing on the spin wave (green wavy lines) (Credit: Yacoby Lab/ Harvard SEAS)

Spin waves, a change in electron spin that propagates through a material, could fundamentally change how devices store and carry information. These waves, also known as magnons, don’t scatter or couple with other particles. Under the right conditions, they can even act like a superfluid, moving through a material with zero energy loss.

Read the full story Posted: Dec 15,2021

Researchers combine two cognitive computing nano-elements into one

Researchers at Tohoku University and the University of Gothenburg have designed a new spintronics technology for brain-inspired computing.

Sophisticated cognitive tasks, such as image and speech recognition, have seen recent breakthroughs thanks to deep learning. Even so, the human brain still executes these tasks without exerting much energy and with greater efficiency than any computer. The development of energy-efficient artificial neurons capable of emulating brain-inspired processes has therefore been a major research goal for decades.

Read the full story Posted: Dec 07,2021

Researchers design a system that demonstrates unusually long-range Josephson coupling across a half-metallic ferromagnet

An international team has, for the first time, designed a material system that exhibits an unusually long-range Josephson effect. Regions of superconducting YBa2Cu3O7 are separated by a region of half-metallic, ferromagnetic manganite (La2/3Sr1/3MnO3) one micron wide.

When two superconducting regions are separated by a strip of non-superconducting material, a special quantum effect can occur, coupling both regions. This is known as the Josephson effect. If the spacer material is a half-metal ferromagnet, it can open up new potential applications for novel spintronic applications.

Read the full story Posted: Dec 05,2021

Researchers find new topological magnet with colossal angular magnetoresistance

A research team led by Prof. Kim Jun Sung in the Center for Artificial Low Dimensional Electron Systems within the Institute for Basic Science (IBS, South Korea) and Physics Department at Pohang University of Science and Technology (POSTECH, South Korea) has found a new magnetotransport phenomenon, in the magnetic semiconductor Mn3Si2Te6. The group found that the magnitude of change in resistance can reach as much as a billion-fold under a rotating magnetic field. This unprecedented shift of resistance depending on magnetic field angle is called colossal angular magnetoresistance (CAMR).

A key challenge in spintronics is finding an efficient and sensitive way to electrically detect the electronic spin state. For example, the discovery of giant magnetoresistance (GMR) in the late 1980s, allowed for such functionality. In GMR, a large change in electrical resistance occurs under the magnetic field depending on parallel or antiparallel spin configurations of the ferromagnetic bilayer. The discovery of GMR has led to the development of hard-disk drive technology, which is technically the first-ever mass-produced spintronic device. Since then, discoveries of other related phenomena, including colossal magnetoresistance (CMR) which occurs in the presence of a magnetic field, have advanced our understanding of the interplay between spin and charge degrees of freedom and served as a foundation of emergent spintronic applications.

Read the full story Posted: Nov 26,2021

Researchers demonstrate non-volatile control of spin-to-charge conversion in germanium telluride

A team of researchers at Politecnico di Milano, University Grenoble Alpes and other institutes worldwide have recently demonstrated the non-volatile control of the spin-to-charge conversion in germanium telluride, a known Rashba semiconductor, at room temperature. Their work could have important implications for the future development of spintronic devices.

The Rashba effect, discovered in 1959, entails a momentum-independent splitting of spin bands in two-dimensional condensed matter systems. In ferroelectric Rashba semiconductors, this effect can be reversed by switching the direction of the ferroelectric polarization. The idea that Rashba spin-splitting in these materials can be controlled was confirmed by a series of first-principle calculations by S. Picozzi and later validated in spectroscopic experiments using germanium telluride, which is thus often considered the 'prototype' of the ferroelectric Rashba class of semiconductors.

Read the full story Posted: Nov 14,2021