Search

We studied, by micromagnetic simulations, the characteristic propagation behaviors of specific spin-wave modes along narrow domain walls in a specially designed thin-film-nanostrip cross-structure waveguide as well as their novel interaction behaviors with a single magnetic vortex placed at the cross-point. Only certain specific modes of spin waves well propagate along the given domain walls and then interact with the magnetic vortex. Through this robust interaction, vortex-gyration motions are also stimulated, which exhibit circular- and/or elliptical-shape core trajectories at the same frequencies as those of the pumping spin waves. The elliptical core trajectories of the stimulated vortex gyrations can be interpreted by the superposition of different amplitudes and phases of the clockwise and counterclockwise circular eigenmodes. According to the action–reaction effect, the phase and the amplitude of the propagating spin waves that pass through the vortex structure are modified differently into different arms of the nanostrip cross-structure. Thereby, the propagating spin waves are allowed to be transmitted and scattered with contrasting phases and amplitudes in different branch arms. This work provides a fundamental understanding of the interaction of spin waves propagating along domain walls with a magnetic soliton and also suggests potential applications to magnonic information processing devices.

We conceptually designed a robust nano-scale waveguide structure suitable for potential use as a spin-wave duplexer that allows signal propagation only of selected narrow-band frequencies and duplex transmission in a three-port device comprising a receiver, a transmitter, and their common antenna. The waveguide structure combines three different arms and a circular ring, both made of nanostrip waveguides and a single magnetic material for reliably controllable propagations of spin waves. We attribute the observed duplex transmission of spin waves of narrow pass bands to scattering of spin waves by edge solitons placed at contact areas between the arms and the circular ring. This work proposes the first concept of nano-scale magnonic duplexers operating beyond GHz-frequency ranges.

The electrodynamics of free carriers in the semimetallic Dirac material $\mathrm{SrMnB}{\mathrm{i}}_{2}$ was investigated using optical spectroscopy and first-principles calculations. Using a two-carrier-model analysis, the total free-carrier response was successfully decomposed into individual contributions from Dirac fermions and non-Dirac free carriers. Possible roles of chiral pseudospin, spin-orbit interaction (SOI), antiferromagnetism, and electron-phonon $(e\text{\ensuremath{-}}ph)$ coupling in the Dirac fermion transport were also addressed. The Dirac fermions possess a low scattering rate of $\ensuremath{\sim}10\phantom{\rule{0.16em}{0ex}}\mathrm{meV}$ at low temperature and thereby experience coherent transport. However, at high temperatures, we observed that the Dirac fermion transport becomes significantly incoherent, possibly due to strong $e\text{\ensuremath{-}}ph$ interactions. The SOI-induced gap and antiferromagnetism play minor roles in the electrodynamics of the free carriers in $\mathrm{SrMnB}{\mathrm{i}}_{2}$. We also observed a seemingly optical-gap-like feature near 120 meV, which emerges at low temperatures but becomes filled in with increasing temperature. This gap-filling phenomenon is ascribed to phonon-assisted indirect transitions promoted at high temperatures.

Background and Purpose While performing respiratory training, an elastic chest band has great benefits for clinical use due to its safety and easy application. However, to our knowledge, there is no published data on the clinical use of an elastic chest band into inspiratory training for people with limited rib mobility. This study aimed to investigate the effects of an elastic chest band integrated into inspiratory exercise for people with decreased chest function. Method Sixteen subjects with limited rib mobility were randomly assigned to either experimental group (EG) or control group (CG), with eight subjects in each group. All subjects received an inspiratory exercise using incentive spirometer for 30 minutes. For the subjects of the EG, an elastic chest band was incorporated into the inspiratory exercises to provide compressive resistance to the chest. The chest function was measured using an electronic spirometer to determine the vital capacity (VC), tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume, forced vital capacity (FVC), forced expiratory volume (FEV), FEV in 1-second (FEV1) and the ratio of FEV1 to FVC (FEV1%). Results Significant differences were found for the VC, TV, IRV, FVC and FEV1 between pre-test and post-test in the two groups (p

Authors present optical spectroscopy measurements of 5d transition metal oxide Sr${}_{2}$IrO${}_{4}$. The results are interpreted in terms of orbital-dependent electron-phonon interaction and are essential for understanding the physics of this material.

While performing respiratory training, an elastic chest band has great benefits for clinical use due to its safety and easy application. However, to our knowledge, there is no published data on the clinical use of an elastic chest band into inspiratory training for people with limited rib mobility. This study aimed to investigate the effects of an elastic chest band integrated into inspiratory exercise for people with decreased chest function.Sixteen subjects with limited rib mobility were randomly assigned to either experimental group (EG) or control group (CG), with eight subjects in each group. All subjects received an inspiratory exercise using incentive spirometer for 30 minutes. For the subjects of the EG, an elastic chest band was incorporated into the inspiratory exercises to provide compressive resistance to the chest. The chest function was measured using an electronic spirometer to determine the vital capacity (VC), tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume, forced vital capacity (FVC), forced expiratory volume (FEV), FEV in 1-second (FEV₁) and the ratio of FEV₁ to FVC (FEV₁ %).Significant differences were found for the VC, TV, IRV, FVC and FEV₁ between pre-test and post-test in the two groups (p 0.05). Further, the changes in the values of VC (0.47 L vs. 0.22 L), FVC (0.55 L vs. 0.25 L) and FEV₁ (0.65% vs. 0.21%) in the EG subjects were significantly greater than those in the CG subjects (p 0.05).These findings suggest that an elastic chest band combined with inspiratory exercise produces additional positive effect on improving chest function in people with limited rib mobility.