Spintronics-Info: the spintronics experts

Researchers from Japan's Tokyo Institute of Technology, National Institute for Materials Science and National Institute of Advanced Industrial Science and Technology have found that lead-based vacancy centers in diamonds, that form after high-pressure and high-temperature treatment, are ideal for quantum networks, spintronics and quantum sensors.

The color in a diamond comes from a defect, or “vacancy,” where there is a missing carbon atom in the crystal lattice. Vacancies have long been of interest to electronics researchers because they can be used as ‘quantum nodes’ or points that make up a quantum network for the transfer of data. One of the ways of introducing a defect into a diamond is by implanting it with other elements, like nitrogen, silicon, or tin. In their recent study, the scientists from Japan demonstrated that lead-vacancy centers in diamond have the right properties to function as quantum nodes. “The use of a heavy group IV atom like lead is a simple strategy to realize superior spin properties at increased temperatures, but previous studies have not been consistent in determining the optical properties of lead-vacancy centers accurately,” says Associate Professor Takayuki Iwasaki of Tokyo Institute of Technology (Tokyo Tech), who led the study.

The attractive properties of Sr₂RuO₄, like its ability to carry lossless electrical currents and magnetic information simultaneously, make it a material with great potential for the development of future technologies like superconducting spintronics and quantum electronics. An international research team, led by scientists at the University of Konstanz, was recently able to answer one of the most interesting open questions on Sr₂RuO₄: why does the superconducting state of this material exhibit some features that are typically found in materials known as ferromagnets, which are considered being antagonists to superconductors?

Spin polarized muon particles (red spheres with arrows) probing a new form of magnetism in the perovskite superconductor Sr2RuO4. Credit: Konstanz University

The team has found that the material hosts a new form of magnetism, which can coexist with superconductivity and exists independently of superconductivity as well.

Scientists from Australia's Monash University (affiliated with Fleet, the Australian research council funded ‘Arc Centre of Excellence in Future low-energy Electronics Technologies’) have discovered how magnetism occurs in 2D ‘kagome’ metal-organic frameworks, opening the door to self-assembling controllable nano-scale electronic and spintronic devices.

Kagome materials have repeating patterns of hexagons and smaller triangles, with the hexagons touching at their tips. The word 'Kagome' comes from Japanese, relating to a basket weaving pattern.

Researchers at CIC nanoGUNE BRTA in Spain and University of Regensburg in Germany have recently demonstrated spin precession at room temperature in the absence of a magnetic field in bilayer graphene. In their paper, the team used 2D materials to realize a spin field-effect transistor.

Sketch of the spin field-effect transistor. Image from article

Coherently manipulating electron spins at room temperature using electrical current is a major goal in spintronics research. This is particularly valuable as it would enable the development of numerous devices, including spin field-effect transistors. In experiments using conventional materials, engineers and physicists have so far only observed coherent spin precession in the ballistic regime and at very low temperatures. Two-dimensional (2D materials), however, have unique characteristics that could provide new control knobs to manipulate spin procession.

Rice University researchers have confirmed the topological origins of magnons, magnetic features they discovered three years ago in a 2D material that could prove useful for encoding information in the spins of electrons.

The discovery provides a new understanding of topology-driven spin excitations in materials known as 2D van der Waals magnets. The materials are of growing interest for spintronics - for computation, storage and communications.

An international team of researchers has presented a finding that could help to identify exotic quantum states. The team seen strongly competing factors that affect an electron's behavior in a high-quality quantum material.

As an electron moves, its motion and spin can become linked through an effect known as spin–orbit coupling. This effect is useful because it offers a way to externally control the motion of an electron depending on its spin—a vital ability for spintronics. Spin–orbit coupling is a complex mix of quantum physics and relativity, but it becomes easier to understand by envisioning a round soccer ball. "If a soccer player kicks the ball, it flies on a straight trajectory," explains Denis Maryenko of the RIKEN Center for Emergent Matter Science. "But if the player gives the ball some rotation, or spin, its path bends." The ball's trajectory and its spinning motion are connected. If its spinning direction is reversed, the ball's path will bend in the opposite direction.

Researchers from Daegu Gyeongbuk Institute of Science and Technology (DGIST) in Korea have demonstrated a novel route to tune and control the magnetic domain wall motions employing combinations of useful magnetic effects inside very thin film materials. The research offers a new insight into spintronics and a step towards new ultrafast, ultrasmall, and power-efficient IT devices.

The new study demonstrates a new way to handle information processing using the movement of the magnetic states of the thin film device. It takes advantage of some unusual effects that occur when materials with contrasting types of magnetic material are squashed together. The research focuses on a device that combines ferromagnetic and antiferromagnetic materials, in which the directions of electron spins align differently within the respective magnetic materials.