Nanowerk June 28, 2021 An international team of researchers (Australia, China) demonstrated that ultra-high electron doping concentration (above 1021 cm-3) can be induced in the layered van der Waals (vdW) metallic material Fe5GeTe2 by proton intercalation and can further cause a transition of the magnetic ground state from ferromagnetism to antiferromagnetism. Compared to itinerant ferromagnets, antiferromagnets (AFMs) have unique advantages as building blocks of such future spintronic devices. Their robustness to stray magnetic fields makes them suitable for memory devices. All the samples showed that the ferromagnetic state can be gradually suppressed by increasing proton intercalation, and finally several samples […]
Category Archives: Spintronics
Controlling magnetization by surface acoustic waves
Nanowerk May 27, 2021 Interconversion between electron spin and other forms of angular momentum is useful for spin-based information processing. Well-studied examples of this are the conversion of photon angular momentum and rotation into ferromagnetic moment. Recently, several theoretical studies have suggested that the circular vibration of atoms work as phonon angular momentum; however, conversion between phonon angular momentum and spin-moment has yet to be demonstrated. Researchers in Japan demonstrated that the phonon angular momentum of surface acoustic wave can control the magnetization of a ferromagnetic Ni film by means of the phononic-to-electronic conversion of angular momentum in a Ni/LiNbO3 […]
Researchers report breakthrough that enables practical semiconductor spintronics
Phys.org April 8, 2021 By remote spin filtering of InAs quantum-dot electrons via an adjacent tunnelling-coupled GaNAs spin filter an international team of researchers (Sweden, Finland, Japan) demonstrated successful generation of conduction electron spin polarization exceeding 90% at room temperature without a magnetic field in a non-magnetic all-semiconductor nanostructure, which remains high even up to 110 °C. They also showed that the quantum-dot electron spin can be remotely manipulated by spin control in the adjacent spin filter, paving the way for remote spin encoding and writing of quantum memory as well as for remote spin control of spin–photon interfaces. This work […]
A new spin on energy-efficient electronics
Phys.org March 30, 2021 An international team of researchers (USA – University of Wisconsin, University of Nebraska, Cornell University, Lawrence Berkeley National Laboratory, Argonne National Laboratory, South Korea, UK, Norway, Ireland) designed a new structure based on antiperovskites to manipulate the flow of spin information without moving the electrons’ charges through the material. Through X-ray diffraction they figured out at what point the structure of the material changed, indicating the emergence of the necessary arrangement of electronic spins. The material develops a magnetic order a little above room temperature. According to the researchers the ability to manipulate the arrangement of […]
Catching electrons in action in an antiferromagnetic nanowire
Science Daily March 16, 2021 A team of researchers in the US (Michigan Technological University, Iowa State University) used a predictive quantum many-body theory that considers electron-electron interactions. The team found that chromium-doped nanowires with a germanium core and silicon shell can be an antiferromagnetic semiconductor. The origin of antiferromagnetic spin alignments between Cr is attributed to the super exchange interaction mediated by the pz orbitals of the Ge atoms that are bonded to Cr. A weak spin–orbit interaction in this material, suggested a longer spin coherence length. The spin-dependent quantum transport calculations in the Cr-doped nanowire junction revealed a […]
Spintronics: New production method makes crystalline microstructures universally usable
Science Daily February 23, 2021 Based on a recently developed method that allows the fabrication of freestanding monocrystalline YIG bridges on gadolinium-gallium-garnet, researchers in Germany have developed a process that allows the transfer of monocrystalline yttrium-iron-garnet microstructures onto virtually any kind of substrate. The bridges’ spans are detached from the substrate by a dry etching process and immersed in a watery solution. Using drop-casting, the immersed YIG platelets can be transferred onto the substrate of choice, where the structures finally can be reattached and, thus, be integrated into complex devices or experimental geometries. They demonstrated that the structures retain their […]
Researchers demonstrate the potential of a new quantum material for creating two spintronic technologies
Phys.org February 3, 2021 Finding materials with the exact characteristics necessary to fabricate Antiferromagnetic (AFM) spintronics has so far proved to be highly challenging. An international team of researchers (USA – UC Berkeley, Lawrence Berkeley National Laboratory, National High Magnetic Field Laboratory, UCLA, Israel) has identified a new quantum material (Fe1/3 + δNbS2) that could be used to fabricate AFM spintronic devices. They demonstrated that antiferromagnetic switching in the intercalated transition-metal dichalcogenide (TMD)-based compounds have a huge ‘exchange bias’, single-pulse saturation and a significantly lower activation energy. They showed that the coexistence of spin glass and antiferromagnetic order allows a […]
Researchers from NUS create ‘whirling’ nano-structures in anti-ferromagnets
EurekAlert February 4, 2021 Special magnetic nano-patterns in anti-ferromagnets that are shaped as whirls or vortices would be quite useful, as they are very stable structures and can potentially be moved along magnetic ‘race tracks’ at speeds of a few kilometres per second. To realize anti-ferromagnetic whirls an international team of researchers (Singapore, UK, USA – University of Wisconsin) combined high-quality film synthesis from materials engineering, phase transitions from physics and topology from mathematics. To grow these materials they fired a laser at iron-oxide. By using ultra-short pulses of laser, they created a hot vapour of atomic particles that formed […]
The long-range transport of deconfined magnetic hedgehogs
Phys.org January 18, 2021 Using magnetic insulators to achieve long-range transport of spins has proved highly challenging. Researchers at UCLA resorted to topological spin textures rather than spins themselves for the purpose of long-range transport. The magnetic hedgehog is one type of topologically protected spin texture that generically exits in three-dimensional magnets. The researchers showed that the hedgehog current is a well conserved quantity and can be explored to achieve long-range transport in magnetic insulators. The study is based on the theoretical construct topological conservation law, which allowed the researchers to leverage the idea of hydrodynamics of topological spin textures. […]
The changing paradigm of next-generation semiconductor memory development
Nanowerk January 12, 2021 It has been reported that spins are formed inside a nanomagnet if electric current is applied to the nanomagnet. There have been no studies on the physical results of these spins. Researchers in South Korea have established a theoretical system by developing a spin diffusion equation that describes the spin conductance in magnetic materials. They discovered that when the spins formed by electric current is emitted to the outside, only the sign is opposite to that of the spins injected from the outside, and the effects are the same. Therefore, the directions of the N pole […]