Phys.org December 11, 2024 The presence of net magnetization limits device scalability and compatibility with phases, such as superconductors and topological insulators. Altermagnetism has been proposed as a solution to these restrictions combined with the antiferromagnetic-like vanishing net magnetization. So far, altermagnetic ordering has been inferred from spatially averaged probes. An international team of researchers (UK, Switzerland, Czech Republic, Germany) demonstrated nanoscale imaging of altermagnetic states from 100-nanometre-scale vortices and domain walls to 10-micrometre-scale single-domain states in manganese telluride. They combined the time-reversal-symmetry-breaking sensitivity of X-ray magnetic circular dichroism with magnetic linear dichroism to achieve maps of the local altermagnetic […]
Category Archives: Magnetism
Researchers create entangled quantum magnets with protected quantum excitations
Phys.org August 29, 2024 Artificial quantum systems have emerged as platforms to realize topological matter in a well-controlled manner. However, the realization of many-body topological phases in solid-state platforms with atomic resolution has remained challenging. An international team of researchers (USA – Stevens Institute of Technology, China, Finland) engineered both topological and trivial phases of the quantum spin model and realized first- and second-order topological quantum magnets. They probed the many-body excitations of the quantum magnets by single-atom electron spin resonance with an energy resolution better than 100 neV. Using the atomically localized magnetic field of the scanning tunnelling microscope tip, […]
Physicists report new insights into exotic particles key to magnetism
Phys.org August 1, 2024 An international team of researchers (USA – MIT, Arizona State University, Brookhaven National Laboratory, France, the Netherlands) studied the impact of charge transfer and magnetic order on the excitation spectrum of the nickel dihalides. They detected sharp excitations, analogous to the recently reported excitons and demonstrated that the excitons were dispersive using momentum-resolved resonant inelastic X-ray scattering. The data showed a ligand-mediated multiplet dispersion, which was tuned by the charge-transfer gap and independent of the presence of long-range magnetic order. According to the researchers this reveals the mechanisms governing nonlocal interactions of on-site intra-atomic transitions between […]
Researchers make a surprising discovery: Magnetism in a common material for microelectronics
Phys.org May 15, 2024 Nickel monosilicide (NiSi) is widely used to connect transistors in semiconductor circuits. Earlier theoretical calculations had incorrectly predicted that NiSi was not magnetic. As a result, researchers had never fully explored magnetism in NiSi. An international team of researchers (USA – University of Missouri, Oak Ridge National Laboratory, Austria, Poland) showed that NiSi metal could provide suitable new platform. The study showed high-temperature antiferromagnetism in single-crystal NiSi with Néel temperature. Antiferromagnetic order in NiSi was accompanied by non-centrosymmetric magnetic character with small ferromagnetic component in the a–c plane. It was found that NiSi manifests distinct magnetic […]
Room-temperature 2D magnet: Electronic-structure insights
Nanowerk March 28, 2024 Iron gallium telluride (Fe3GaTe2), a van der Waals ferromagnet, demonstrated intrinsic ferromagnetism above room temperature. An international team of researchers (USA – Lawrence Livermore National Laboratory, South Korea, China) revealed the electronic structure of Fe3GaTe2 in its ferromagnetic ground state establishing a consistent correspondence between the measured band structure and theoretical calculations, underscoring the significant contributions of the Heisenberg exchange interaction (Jex) and magnetic anisotropy energy to the development of the high-TC ferromagnetic ordering in Fe3GaTe2. They observed substantial modifications to these crucial driving factors through doping, which they attributed to alterations in multiple spin-splitting bands […]
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 […]