Altermagnetism: A new type of magnetism, with broad implications for technology and research

Phys.org  February 14, 2024 Altermagnets have a special combination of the arrangement of spins and crystal symmetries. The spins alternate, as in antiferromagnets, resulting in no net magnetization. Rather than simply canceling out, the symmetries give an electronic band structure with strong spin polarization that flips in direction as you pass through the material’s energy bands resulting in highly useful properties more resemblant to ferromagnets, as well as some completely new properties. An international team of researchers (Switzerland, Germany, Czech Republic, Austria, Colombia, UK) has proved the existence of altermagnetism. They provided the confirmation using photoemission spectroscopy and ab initio […]

First-ever wireless device developed to make magnetism appear in non-magnetic materials

Phys.org  October 30, 2023 Magneto-ionics is a unique approach to control magnetism with electric field for low-power memory and spintronic applications. So far, magneto-ionics has been achieved through direct electrical connections to the actuated material. Researchers in Spain have shown that such control can be achieved wirelessly. Without direct wire contact inducing polarization in the conducting material immersed in the electrolyte, promoted wireless bipolar electrochemistry, an alternative pathway to achieve voltage-driven control of magnetism based on the same electrochemical processes involved in direct-contact magneto-ionics. They achieved significant tunability of magnetization for cobalt nitride thin films, including transitions between paramagnetic and […]

Research shows how topology can help create magnetism at higher temperatures

Phys.org  October 10, 2023 The interplay between magnetism and electronic band topology enriches topological phases and has promising applications. However, the role of topology in magnetic fluctuations has been elusive. A team of researchers in the US (MIT, Harvard University, Argonne National Laboratory, SLAC National Accelerator Laboratory, Oak Ridge National Laboratory, Brookhaven National Laboratory, industry, Rice University) has shown evidence for topology stabilized magnetism above the magnetic transition temperature in magnetic Weyl semimetal candidate CeAlGe. They had clear indication of the presence of locally correlated magnetism within a narrow temperature window well above the thermodynamic magnetic transition temperature. Effective field […]

Physicists discover ‘stacked pancakes of liquid magnetism’

Phys.org  May 10, 2023 Magnetic frustrations and dimensionality play an important role in determining the nature of the magnetic long-range order and how it melts at temperatures above the ordering transition TN. A team of researchers in the US (Rice University, Ames National Laboratory, Iowa State University) used large-scale Monte Carlo simulations to study these phenomena in a class of frustrated Ising spin models in two spatial dimensions. They found that the melting of the magnetic long-range order into an isotropic gas like paramagnet proceeded via an intermediate stage where the classical spins remained anisotropically correlated. The correlated paramagnet existed […]

A four-stroke engine for atoms

Phys.org  July 6, 2022 Electric control of magnetism and magnetic control of ferroelectricity can improve the energy efficiency of magnetic memory and data-processing devices. However, the necessary magnetoelectric switching is hard to achieve, and requires more than just a coupling between the spin and the charge degrees of freedom. An international team of researchers (Italy, Austria, USA – Rutgers University, the Netherlands) showed that an application and subsequent removal of a magnetic field reverses the electric polarization of the multiferroic GdMn2O5, thus required two cycles to bring the system back to the original configuration. During this unusual hysteresis loop, four […]

A new dimension in magnetism and superconductivity launched

Science Daily  November 3, 2021 In recent studies the impact of curvilinear geometry enters various disciplines, ranging from solid-state physics over soft-matter physics, chemistry, and biology to mathematics. An international team of researchers (Germany, Austria) summarized the state of the art and prospects for future research in curvilinear solid-state systems exhibiting such fundamental cooperative phenomena as ferromagnetism, antiferromagnetism, and superconductivity. Highlighting the recent developments and current challenges in theory, fabrication, and characterization of curvilinear micro- and nanostructures, with emphasis on perspective research directions entailing new physics and to their strong application potential. They aim to cross the boundaries between the […]

Scientists manipulate magnets at the atomic scale

Science Daily  February 12, 2021 An international team of researchers (the Netherlands, Ukraine, Russia, Belgium, UK) shows that light-driven phonons can be utilized to coherently manipulate macroscopic magnetic states. Intense mid-infrared electric field pulses tuned to resonance with a phonon mode of the archetypical antiferromagnet DyFeO3 induce ultrafast and long-living changes of the fundamental exchange interaction between rare-earth orbitals and transition metal spins. Non-thermal lattice control of the magnetic exchange, which defines the stability of the macroscopic magnetic state, allows picosecond coherent switching between competing antiferromagnetic and weakly ferromagnetic spin orders. The discovery emphasizes the potential of resonant phonon excitation […]

Magnetic nanoparticles change their magnetic structure in a magnetic field

Nanowerk  July 27, 2020 Up to now, scientists assumed that magnetism in a nanoparticle is essentially limited to this core area. Using neutron scattering on cobalt ferrite nanoparticles an international team or researchers (France, Germany, Czech Republic) has shown that the applied magnetic field causes some of the previously disordered magnetic moments in the surface region to become aligned, and thus ordered in a way comparable to the magnetization in the core region. However, a residual area with differently aligned spins remains on the surface, which cannot be ordered by the applied magnetic field. Overall, the research showed that the […]