Floquet Engineering the Exceptional Points in Parity-Time-Symmetric Magnonics.

Magnons serve as a testing ground for fundamental aspects of Hermitian and non-Hermitian wave mechanics and are of high relevance for information technology. This study presents setups for realizing spatiotemporally driven parity-time- (PT) symmetric magnonics based on coupled magnetic waveguides and magnonic crystals. A charge current in a metal layer with strong spin-orbit coupling sandwiched between two insulating magnetic waveguides leads to gain or loss in the magnon amplitude depending on the directions of the magnetization and the charge currents.

Magnonic Unidirectional Spin Hall Magnetoresistance in a Heavy-Metal-Ferromagnetic-Insulator Bilayer.

We report the observation of the unidirectional spin Hall magnetoresistance (USMR), which depends on the current or magnetization direction, in heavy-metal-ferromagnetic-insulator bilayer, Pt-Y_{3}Fe_{5}O_{12} (YIG). This USMR is apparently not caused by the mechanisms established in metallic bilayer, in which the ferromagnetic layer is required to be electrically conductive. From the magnetic field, current, temperature, and YIG thickness dependent measurements, the USMR is attributed to the asymmetric magnon creation and annihilation induced by the spin-orbit torque.

Asymmetry in the propagation of vortex domain wall artificial skyrmion composite system.

We studied the propagation of an artificial skyrmion coupled to the vortex domain wall (VDW). We discovered the following effect: depending on the propagation's direction, the dynamics of the coupled skyrmion VDW can be faster than the isolated VDW's velocity. The reason for such behavior is the structural distortion that occurs in the coupled system.

Steering magnonic dynamics and permeability at exceptional points in a parity-time symmetric waveguide.

Tuning the magneto optical response and magnetic dynamics are key elements in designing magnetic metamaterials and devices. This theoretical study uncovers a highly effective way of controlling the magnetic permeability via shaping the magnonic properties of coupled magnetic waveguides separated by a nonmagnetic spacer with strong spin-orbit interaction (SOI). We demonstrate how a spacer charge current leads to enhancement of magnetic damping in one waveguide and a decrease in the other, constituting a bias-controlled magnetic parity-time (PT) symmetric system at the verge of the exceptional point where magnetic gains/losses are balanced.

Fungal communities in sediments of subtropical Chinese seas as estimated by DNA metabarcoding.

Ribosomal RNA internal transcribed spacer-1 (ITS1) metabarcoding was used to investigate the distribution patterns of fungal communities and the factors influencing these patterns in subtropical Chinese seas, including the southern and northern Yellow Sea and the Bohai Sea. These seas were found to harbor high levels of fungal diversity, with 816 operational taxonomic units (OTUs) that span 130 known genera, 36 orders, 14 classes and 5 phyla. Ascomycota was the most abundant phylum, containing 72.

Domain wall motion driven by adiabatic spin transfer torque through excitation of nonlinear dynamics.

Domain wall dynamics under the joint action of a linearly polarized microwave magnetic field and spin transfer torque was analysed in terms of the domain wall collective coordinates. It was found that a microwave-assisted steady domain wall motion driven by adiabatic spin transfer torque can be adequately described by three domain wall collective coordinates. Analytical expression for the domain wall velocity showed that there are two contributions to the steady domain wall motion.