A5041340821- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Magnetic Properties and Applications
- Magneto-Optical Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- Advanced Memory and Neural Computing
- ZnO doping and properties
- Theoretical and Computational Physics
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Characterization and Applications of Magnetic Nanoparticles
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Surface and Thin Film Phenomena
- Electronic and Structural Properties of Oxides
- Acoustic Wave Resonator Technologies
- Magnetic Properties of Alloys
- Advanced Materials Characterization Techniques
- Mechanical and Optical Resonators
- Neural Networks and Applications
- Magnetic Field Sensors Techniques
- Photonic Crystals and Applications
- Advanced SAR Imaging Techniques
- Topological Materials and Phenomena
- Surface Roughness and Optical Measurements
Kyoto University
2015-2024
Kyushu University
2017-2024
Nagoya University
2012-2024
Japan Science and Technology Agency
2003-2024
Spintronics Research Network of Japan
2018-2024
Kyoto University Institute for Chemical Research
2014-2023
Kyoto Bunkyo University
2014-2023
Instituto de Investigaciones Químicas
2015-2023
Niigata University
1996-2022
Tsurugi Hospital
2022
Spintronics utilizing antiferromagnetic materials has potential for the next generation of applications and offers opportunities new ideas. Ultimately, antiferromagnets could replace ferromagnets as active spin-dependent element on which spintronic devices are based. Central to this endeavor is need predictive models, relevant disruptive materials, experimental designs. This paper reviews effects described based theoretical analysis materials.
We demonstrate that the spin Hall effect in a thin film with strong spin-orbit scattering can excite magnetic precession an adjacent ferromagnetic film. The flow of alternating current through Pt/NiFe bilayer generates oscillating transverse Pt, and resultant transfer angular momentum to NiFe induces resonance (FMR) dynamics. Oersted field from also FMR signal but different symmetry. ratio these two signals allows quantitative determination angle.
A four-component scattering model is proposed to decompose polarimetric synthetic aperture radar (SAR) images. The covariance matrix approach used deal with the nonreflection symmetric case. This scheme includes and extends three-component decomposition method introduced by Freeman Durden dealing reflection symmetry condition that co-pol cross-pol correlations are close zero. Helix power added as fourth component which describes surface, double bounce, volume scattering. helix term take...
For a long time, there were no efficient ways of controlling antiferromagnets. Quite strong magnetic field was required to manipulate the moments because high molecular and small susceptibility. It also difficult detect orientation since net moment is effectively zero. these reasons, research on antiferromagnets has not been progressed as drastically that ferromagnets which are main materials in modern spintronic devices. Here we show NiO, typical natural antiferromagnet, can indeed be...
We prepare the high quality epitaxial MgO(001)[100]/Pt(001)[100]/NiO(001)[100]/FeNi/SiO2 films to investigate spin transport in NiO antiferromagnetic insulator. The ferromagnetic resonance measurements of FeNi under a current injection from Pt by Hall effect revealed change linewidth depending on amount injection. results can be interpreted that there is an angular momentum transfer through NiO. A efficient we observed attributed well-defined orientation moments and quantization axis...
Here, the authors clarify physical origin of anomalies in transverse resistivity often observed exotic materials, such as SrRuO${}_{3}$, where Berry curvature is manifested transport properties. Their thorough magnetotransport investigations and model formulations reveal that previously attributed mechanism for -- topological Hall effect not only interpretation. They show inhomogeneous magnetoelectric properties oxide, namely coexistence anomalous effects having different polarities, are...
We report the experimental observation of Snell's law for magnetostatic spin waves in thin ferromagnetic Permalloy films by imaging incident, refracted, and reflected waves. use a thickness step as interface between two media with different dispersion relations. Since relation is anisotropic, deviations from isotropic known optics are observed incidence angles larger than 25° respect to normal magnetic media. Furthermore, we can show that modifies wavelength amplitude incident Our findings...
We report an experimental observation of magnon-magnon coupling in interlayer exchange coupled synthetic antiferromagnets FeCoB/Ru/FeCoB layers. An anticrossing gap spin-wave resonance between acoustic and optic modes appears when the external magnetic field points to direction tilted from propagation. The magnitude (i.e., strength) can be controlled by changing in-plane also enhanced increasing wave number excited spin waves. find that strength under specified conditions is larger than...
B2-ordered FeRh has been known to exhibit antiferromagnetic-ferromagnetic (AF-F) phase transitions in the vicinity of room temperature. Manipulation N\'eel order via AF-F transition and recent experimental observation anisotropic magnetoresistance antiferromagnetic proven that is a promising candidate for memory material. In this work, we demonstrate sequential write read operations resistors made B2-orderd thin films by magnetic field electric current only. Our demonstration writing reading...
The nonreciprocity of propagating spin waves, i.e., the difference in amplitude and/or frequency depending on propagation direction, is essential for realization wave-based logic circuits. However, nonreciprocal shifts demonstrated so far are not large enough applications because they originate from interfacial effects. In addition, switching wave electrical way remains a challenging issue. Here, we show switchable giant shift waves interlayer exchange-coupled synthetic antiferromagnets....
The acetal (O-glycoside) bonds of glycans and glycoconjugates are chemically biologically vulnerable, therefore C-glycosides interest as more stable analogs. We hypothesized that, if the O-glycoside linkage plays a vital role in glycan function, biological activities C-glycoside analogs would vary depending on their substituents. Based this idea, we adopted "linkage-editing strategy" for creation (pseudo-glycans). designed three types pseudo-glycans with CH2 CHF linkages, which resemble...
We present the results of a perpendicular magnetic tunnel junction (MTJ) that displays simultaneously low critical switching current and voltage, as well high thermal stability factor. These were achieved using free layer MgO/CoFeB/MgO structure by increasing spin torque efficiency to an average 3.0 kBT/µA for 37-nm-diameter junctions, about three times MgO/CoFeB/Ta layer, which makes it highest value reported date. By comparing two films with different RA, hence voltage power, we explore...
Harmonic Hall measurements were performed in Pt/GdFeCo bilayers to quantify the effective field resulting from spin-orbit torque at various temperatures, both above and below magnetization compensation temperature (TM). We found that damping-like rapidly increased near TM of GdFeCo, which was attributed a reduction net magnetic moment. Moreover, most importantly, spin efficiency turned out be constant across range.
Chiral spin textures of a ferromagnetic layer in contact to heavy non-magnetic metal, such as Néel-type domain walls and skyrmions, have been studied intensively because their potential for future nanomagnetic devices. The Dyzaloshinskii-Moriya interaction (DMI) is an essential phenomenon the formation chiral textures. In spite recent theoretical progress aiming at understanding microscopic origin DMI, experimental investigation unravelling physics stake still required. Here we...
A tabletop setup for imaging antiferromagnetic order shows how electron spin domains in a thin film of NiO respond to an external electric current, useful insight building fast computer memories.
We investigate the Gilbert damping parameter α for rare earth (RE)-transition metal (TM) ferrimagnets over a wide temperature range. Extracted from field-driven magnetic domain-wall mobility, was as low order of 10^{-3} and almost constant across angular momentum compensation T_{A}, starkly contrasting previous predictions that should diverge at T_{A} due to vanishing total momentum. Thus, RE-TM is not related but dominated by electron scattering Fermi level where TM has dominant role. This...