Phys.org September 24, 2024 Current-driven antiferromagnetic order switching has implications for next-generation spintronic devices. Some reports have claimed that demagnetization above the Néel temperature due to Joule heating is critical for switching. University of Illinois at Urbana-Champaign presented a systematic method and an analytical model to quantify the thermal contribution due to Joule heating in micro-electronic devices, focusing on current-driven octupole switching in the non-collinear antiferromagnet, Mn3Sn. Their results consistently showed that the critical temperature for switching remained relatively constant above the Néel temperature, while the threshold current density depended on the choice of substrate and the base temperature. They […]
Category Archives: Spintronics
‘Miracle’ filter turns store-bought LEDs into spintronic devices
Phys.org July 25, 2024 Current efforts to enable a broader range of optoelectronic functionality are limited because of inherent inefficiencies associated with spin injection across semiconductor interfaces. An international team of researchers (USA – National Renewable Energy Laboratory (NREL), University of Utah, Colorado School of Mines, University of Colorado, France) demonstrated spin injection across chiral halide perovskite/III–V interfaces achieving spin accumulation in a standard semiconductor III–V (AlxGa1−x)0.5In0.5P multiple quantum well light-emitting diode. The spin accumulation was detected through emission of circularly polarized light with a degree of polarization of up to 15 ± 4%. The chiral perovskite/III–V interface characterized with X-ray photoelectron […]
Spintronics: A new path to room temperature swirling spin textures
Science Daily April 17, 2024 In spintronics the generation and stabilization of most of the magnetic textures is restricted to a few materials and achievable under very specific conditions (temperature, magnetic field…). Recently, a new approach has shown potential for the imprint of magnetic radial vortices in soft ferromagnetic compounds making use of the stray field of YBa2Cu3O7-δ superconducting microstructures in ferromagnet/superconductor (FM/SC) hybrids at temperatures below the superconducting transition temperature (TC). Using a new approach an international team of researchers (France, Spain, Germany) explored the lower size limit for the imprint of magnetic radial vortices in square and disc […]
Spintronics research shows material’s magnetic properties can predict how a spin current changes with temperature
Phys.org April 23, 2024 An international team of researchers (Japan, Australia) examined magnon spin currents in the ferrimagnetic garnet Tb3Fe5O12 with 4f electrons through the spin-Seebeck effect and neutron scattering measurements. The compound showed a magnetic compensation, where the spin-Seebeck signal reversed above and below K. Unpolarized neutron scattering unveiled two major magnon branches with finite energy gaps which were well explained in the framework of spin-wave theory. Their temperature dependencies and the direction of the precession motion of magnetic moments defined using polarized neutrons explained the reversal at and decay of the spin-Seebeck signals at low temperatures. According to […]
Study hints at new way to improve on spintronics for future tech
Nanowerk October 13, 2023 An international team of researchers (USA- Ohio State University, Sweden, UK) used a new method involving the reflection of polarized light on thin films of light metal chromium, successfully detected the orbital Hall effect. The orbital polarization was in-plane, transverse to the current direction, and scaled linearly with current density, consistent with the orbital Hall effect. Comparing the thickness-dependent magneto-optical measurements with ab initio calculations, they estimated an orbital diffusion length in Cr of 6.6±0.6nm. The potential application of this discovery in spintronics could lead to improve data storage in the next generation of computer devices […]
Laser light hybrids control giant currents at ultrafast times
Phys.org April 13, 2023 Spin and valley indices represent the key quantum labels of quasi-particles in a wide class of two-dimensional materials and form the foundational elements of the fields of spintronics and valleytronics. Researchers in Germany have discovered a route to induce and control the flow of spin and valley currents at ultrafast times with specially designed laser pulses, offering a new perspective on the ongoing search for the next generation of information technologies. They showed that femtosecond laser light combining optical frequency circularly polarized pulse and a terahertz (THz) frequency linearly polarized pulse can generate precisely tailored and […]
Single-electron devices could manage heat flow in electronic components
Nanowerk December 8, 2022 Previous heat engines based on quantum dots have used reservoirs of electrons at different temperatures. An international team of researchers (Japan, Germany) has fabricated a nanoscale ‘heat engine’ that uses a property of spin as the effective working medium. They confined electrons using electric fields generated at surface metal electrodes on a gallium arsenide surface. The device had two interlinked quantum dots and a built-in charge sensor to passively monitor what was going on within the double quantum dot. A third quantum dot was used to control the double quantum dot’s thermal environment. According to the […]
Novel nanowire fabrication technique paves way for next generation spintronics
Nanowerk November 9, 2022 Eliminating the etching process by directly fabricating nanowires onto the silicon substrate would lead to a marked improvement in the fabrication of spintronic devices. However, when directly fabricated nanowires are subjected to annealing, they tend to transform into droplets as a result of the internal stresses in the wire. Researchers in Japan have developed a new fabrication process to make L10-ordered CoPt nanowires on silicon/silicon dioxide (Si/SiO2) substrates. They coated a Si/SiO2 substrate with a material called a ‘resist’ and subjected it to electron beam lithography and evaporation to create a stencil for the nanowires, deposited […]
One-unit-cell thick semiconductors with room-temperature magnetism
Nanowerk November 15, 2022 Researchers in China have developed a confined-van der Waals epitaxial approach to synthesizing air-stable semiconducting cobalt ferrite nanosheets with thickness down to one unit cell using a facile chemical vapor deposition process. They demonstrated hard magnetic behavior and magnetic domain evolution by means of vibrating sample magnetometry, magnetic force microscopy and magneto-optical Kerr effect measurements, which showed high Curie temperature above 390 K and strong dimensionality effect. According to the researchers their work provides possibilities for numerous novel applications in computing, sensing and information storage…read more. Open Access TECHNICAL ARTICLE
Researchers develop a material that mimics how the brain stores information
Nanowerk November 8, 2022 While a precise modulation of magnetism is achieved when voltage is applied, much more uncontrolled is the spontaneous evolution of magneto-ionic systems upon removing the electric stimuli. An international team of researchers (Spain, Italy, Belgium) has demonstrated a voltage-controllable N ion accumulation effect at the outer surface of CoN films adjacent to a liquid electrolyte, which allows for the control of magneto-ionic properties both during and after voltage pulse actuation (i.e., stimulated, and post-stimulated behavior, respectively). This effect, which takes place when the CoN film thickness is below 50 nm and the voltage pulse frequency is […]