Researchers use heat to drive topological spin texture transformations

Researchers at Japan's RIKEN have conducted an experiment that could help the development of new energy-efficient spintronics devices. They used heat and magnetic fields to create transformations between spin textures—magnetic vortices and antivortices known as skyrmions and antiskyrmions—in a single crystal thin plate device. What's even more important is that they achieved this at room temperature.

Skyrmions and antiskyrmions, which are textures that exist within special magnetic materials involving the spin of the electrons in the material, are an active area of research, as they could be used for next-generation memory devices, for example, with skyrmions acting as a "1" bit and antiskyrmions a "0" bit. In the past, scientists have been able to move them in a variety of ways, and to create transformations between them using electric current. However, because current electronic devices consume electrical power and produce waste heat, the researchers in the group, led by Xiuzhen Yu at the RIKEN Center for Emergent Matter Science, decided to see if they could find a way to create the transformations using heat gradients.

Read the full story Posted: Jan 13,2024

Researchers demonstrate strain-induced orbital control in an interfacial multiferroic material

A Japanese research team, led by Jun Okabayashi from the University of Tokyo, including Associate Professor Yoshihiro Gohda from Tokyo Tech and Osaka University researchers, recently revealed a strain-induced orbital control mechanism in interfacial multiferroics. 

Controlling the direction of magnetization using low electric field is important for achieving efficient spintronic devices. In spintronics, properties of an electron's spin or magnetic moment are used to store information. The electron spins can be manipulated by straining orbital magnetic moments to create a high-performance magnetoelectric effect.

Read the full story Posted: Jan 12,2024

Researchers use Berry phase monopole engineering for high-temperature and low-power spintronic devices

Researchers at Japan's Tokyo Institute of Technology (Tokyo Tech) have demonstrate the concept of Berry phase monopole engineering of the spin Hall effect in non-centrosymmetric silicide TaSi2.

Image credit: Tokyo Tech

Spin-transfer torque is an important phenomenon that enables ultrafast and low-power spintronic devices. Recently, however, spin-orbit torque (SOT) has emerged as a promising alternative to spin-transfer torque. Many studies have investigated the origin of SOT, showing that in non-magnetic materials, a phenomenon called the spin Hall effect (SHE) is key to achieving SOT. In these materials, the existence of a “Dirac band” structure, a specific arrangement of electrons in terms of their energy, is important to achieving large SHE. This is because the Dirac band structure contains “hot spots” for the Berry phase, a quantum phase factor responsible for the intrinsic SHE. Thus, materials with suitable Berry phase hot spots are key to engineering the SHE.

Read the full story Posted: Jan 07,2024

Researchers report spintronics-based probabilistic computers compatible with current AI

Researchers at Tohoku University and the University of California, Santa Barbara, have shown a proof-of-concept energy-efficient computer compatible with current AI. It utilizes a stochastic behavior of nanoscale spintronics devices and is particularly suitable for probabilistic computation problems such as inference and sampling.

The team presented the results at the IEEE International Electron Devices Meeting (IEDM 2023) on December 12, 2023.

Read the full story Posted: Dec 14,2023

Researchers find large spin–orbit torque in bismuthate-based heterostructures

Scientists at the University of Wisconsin–Madison, University of California, Cornell University, University of Nebraska, Arizona State University and Tsinghua University have found a unique property of the material Ba(Pb,Bi)O3: it exhibits extremely high spin orbit torque, a property useful in the field of spintronics. The materials was previously found to act as a rare type of superconductor that could operate at higher temperatures. 

The combination of these two properties makes this and similar materials potentially important in developing the next generation of fast, efficient memory and computing devices.

Read the full story Posted: Dec 06,2023

Researchers induce robust spin-polarization in graphene for low-power electronics

Researchers at the National University of Singapore (NUS), University of Science and Technology of China and the National Institute for Materials Science in Japan have developed a way to induce and directly quantify spin splitting in two-dimensional materials. 

Using this concept, they have experimentally achieved large tunability and a high degree of spin-polarization in graphene. This research achievement can potentially advance the field of two-dimensional (2D) spintronics, with applications for low-power electronics.

Read the full story Posted: Nov 25,2023

Researchers present experimental evidence of hopfion rings in a cubic chiral magnet

Researchers from Beijing University of Technology, South China University of Technology, Forschungszentrum Jülich and Uppsala University have reported the first experimental evidence of hopfions, which are magnetic spin structures predicted decades ago that have become a fascinating research topic in recent years.

The team used transmission electron microscopy to observe hopfions forming coupled states with skyrmion strings in B20-type FeGe plates. They provided a protocol for nucleating such hopfion rings, which they verified using Lorentz imaging and electron holography. The scientists' results are said to be highly reproducible and in full agreement with micromagnetic simulations. 

Read the full story Posted: Nov 23,2023

Realizing magnetic-field-free spintronic Thz emitters

Dr. Darren M. Graham, an associate professor from the University of Manchester, has given an interesting talk recently, titled "Exploiting magnetic anisotropy: realizing magnetic-field-free spintronic THz emitters and polarization control".

Check out the video above for the complete lecture recording.

Read the full story Posted: Nov 22,2023

Researchers confirm dynamics of skyrmion spin states in neutron-scattering experiments

Researchers from Japan's RIKEN Center for Emergent Matter Science (CEMS) and Ochanomizu University, UK's  University of Birmingham, Sweden's Lund University, Canada's Université de Sherbrooke, Czech Republic's Nuclear Physics Institute, France's Institut Max von Laue-Paul Langevin (ILL) have advanced low-energy devices based on spintronics, by measuring the dynamics of tiny magnetic vortices.

The team examined the low-energy excitations of the skyrmion state in MnSi by using the neutron spin-echo technique under small-angle neutron scattering conditions. The scientists observed an asymmetric dispersion of the phason excitations of the lattice because of the string-like structure of the skyrmion cores.

Read the full story Posted: Nov 13,2023

Researchers propose chemical method for reversible Magnetic phase transition in 2D organometallic lattices

Researchers from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), led by Associate Prof. Li Xingxing and Prof. Yang Jinlong, recently developed a novel chemical method for two-dimensional metal-organic lattices.

In spintronics, it is paramount to develop an efficient way to reversibly control the spin order of materials. Though various physical methods have been proposed, chemically achieving this has posed significant challenges. The researchers proposed the utilization of the well-recognized lactim−lactam tautomerization process to reversibly modulate the magnetic phase transition in two-dimensional (2D) organometallic lattices. This could offer new pathways for controlling the electrical and magnetic characteristics of materials.

Read the full story Posted: Nov 11,2023