Phys.org September 22, 2024 Non-centrosymmetric polar conductors are intrinsic diodes that could be of use in the development of nonlinear applications. Such systems have recently been extended to non-centrosymmetric superconductors. An international team of researchers (USA – Harvard University, Northeastern University, MIT, UCLA, Boston College, Taiwan, India, Japan) has reported antiferromagnetic diode effect in a centrosymmetric crystal without directional charge separation. Large second-harmonic transport in a nonlinear electronic device enabled by the compensated antiferromagnetic state of even-layered MnBi2Te4. They showed that this antiferromagnetic diode effect could be used to create in-plane field-effect transistors and microwave-energy-harvesting devices, and electrical sum-frequency generation […]
Tag Archives: Antiferromagnetism
Thermal effects in spintronics systematically assessed for first time
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 […]
Physicists manipulate magnetism with light
Nanowerk January 28, 2022 The non-equilibrium driving of dressed quasiparticles offers a promising platform for realizing unconventional many-body phenomena and phases beyond thermodynamic equilibrium. An international team of researchers (USA – MIT, South Korea) achieved this in the van der Waals correlated insulator NiPS3 by photoexciting its newly discovered spin–orbit-entangled excitons that arise from Zhang-Rice states. By monitoring the time evolution of the terahertz conductivity, they observed the coexistence of itinerant carriers produced by exciton dissociation and a long-wavelength antiferromagnetic magnon that coherently processes in time. These results demonstrate the emergence of a transient metallic state that preserves long-range antiferromagnetism, […]
On the road to faster and more efficient data storage
Phys.org August 18, 2021 Antiferromagnet is a promising candidate for developing the next generation of information technology. An international team of researchers (Germany, Sweden, Japan, Italy) showed that domain walls play an active role in the dynamic properties of the antiferromagnet nickel oxide. The experiments revealed that magnetic waves with different frequencies could be induced, amplified, and even coupled with each other across different domains—but only in the presence of domain walls. The ability highlights the potential to actively control the propagation of magnetic waves in time and space as well as energy transfer among individual waves at the femtosecond […]
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 […]