A5062408915- Magnetic properties of thin films
- ZnO doping and properties
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- Semiconductor Quantum Structures and Devices
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Heusler alloys: electronic and magnetic properties
- Heart Rate Variability and Autonomic Control
- Fibromyalgia and Chronic Fatigue Syndrome Research
- Semiconductor materials and interfaces
- Magneto-Optical Properties and Applications
- Advanced Condensed Matter Physics
- Surface and Thin Film Phenomena
- Physics of Superconductivity and Magnetism
- EEG and Brain-Computer Interfaces
- Chalcogenide Semiconductor Thin Films
- Neural and Behavioral Psychology Studies
- Laser Design and Applications
- Telomeres, Telomerase, and Senescence
- Topological Materials and Phenomena
- Magnetic Field Sensors Techniques
- Magnetic Properties and Applications
- Magnetic Properties and Synthesis of Ferrites
Tokyo University of Information Sciences
2011-2025
The University of Tokyo
2016-2025
Spintronics Research Network of Japan
2016-2025
Japan Science and Technology Agency
2004-2023
Osaka City University
2011-2022
Shiga University of Medical Science Hospital
2022
Shinshu University
2017-2021
Osaka Nishi Clinic
2021
Japan Atomic Energy Agency
2020-2021
Shiga University of Medical Science
2021
We study experimentally and theoretically the influence of interface roughness on mobility two-dimensional electrons in modulation-doped AlAs/GaAs quantum wells. It is shown that scattering dominant mechanism thin wells with a well thickness Lw<60 Å, where electron mobilities are proportional to L6w, reaching 2×103 cm2/V s at Lw∼55 Å. From detailed comparison between theory experiment, it determined ‘‘GaAs-on-AlAs’’ grown by molecular beam epitaxy has height 3–5 Å lateral size 50–70
Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disease characterized by chronic, profound, disabling, and unexplained fatigue. Although it hypothesized that brain inflammation involved in the pathophysiology of CFS/ME, there no direct evidence neuroinflammation patients with CFS/ME. Activation microglia or astrocytes related to neuroinflammation. <sup>11</sup>C-(<i>R</i>)-(2-chlorophenyl)-<i>N</i>-methyl-<i>N</i>-(1-methylpropyl)-3-isoquinoline-carboxamide...
It is known that chronic fatigue associated with sympathetic hyperactivity. However, the relationship between autonomic function and mental caused by a prolonged load in healthy humans still unclear. Thus, order to clarify mechanisms underlying fatigue, we examined association functions. The study group comprised 10 participants. To induce participants performed tasks, which consisted of advanced trail making test, kana pick-out test mirror drawing for 8 hr, corresponding normal work day....
We have observed very large tunneling magnetoresistance (TMR) in epitaxially grown ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}/\mathrm{AlAs}/{\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}$ ferromagnetic semiconductor tunnel junctions. Large TMR ratios more than $70%$ (maximum $75%$) were obtained junctions with a thin ( $\ensuremath{\le}1.6\mathrm{nm}$) AlAs barrier when the magnetic field was applied along $[100]$ axis film plane. The found to rapidly...
We propose and theoretically analyze a metal–oxide–semiconductor field-effect-transistor (MOSFET) type of spin transistor (spin MOSFET) consisting MOS structure half-metallic-ferromagnet (HMF) contacts for the source drain. When magnetization configuration HMF drain is parallel (antiparallel), highly spin-polarized carriers injected from to channel are transported into (blocked by) drain, resulting in magnetization-configuration-dependent output characteristics. Our two-dimensional numerical...
Photoluminescence spectra of GaAs-AlAs quantum wells are studied to evaluate the flatness heterointerfaces prepared by molecular beam epitaxy. We examine correlation interface roughness with measured intensity oscillations reflective high energy electron diffraction (RHEED) during growth. The crystal surface is found roughen after growth 10 or more atomic layers. interruption 10–100 seconds prior formation effective in achieving an atomically flat interface, leading sharp photoluminescence...
The interaction between the magnetic dopants (Mn) and 2-dimensional hole gas (2DHG) in Mn \ensuremath{\delta}-doped GaAs/Be-doped $p$-type AlGaAs heterostructures, where holes were supplied from Be-doped to GaAs, realized ferromagnetic ordering. Curie temperature ${T}_{\mathrm{C}}$ of heterostructure prepared with suitable growth conditions was 172 K, highest among values reported III-V (InAs, GaAs) semiconductors.
Abstract Background Fatigue is a crucial sensation that triggers rest, yet its underlying neuronal mechanisms remain unclear. Intense long-term fatigue symptom of chronic syndrome, which used as model to study the fatigue. Methods Using magnetic resonance imaging, we conducted voxel-based morphometry 16 patients and 49 age-matched healthy control subjects. Results We found with syndrome had reduced gray-matter volume in bilateral prefrontal cortex. Within these areas, reduction right cortex...
We have successfully grown ferromagnetic MnGa ultrathin films on GaAs substrates by molecular beam epitaxy. Reflection high energy electron diffraction and cross-sectional transmission microscopy show that monocrystalline are with the c axis of tetragonal unit cell normal to (001) substrates. Both magnetization measurements vibrating sample magnetometer extraordinary Hall effect (EHE) indicate perpendicular magnetization, remnant 225 emu/cm3 EHE resistivity in range 0.5–4 μΩ cm at room...
We have studied template effects in molecular beam epitaxy (MBE) of ferromagnetic MnAs thin films on (001) GaAs substrates. When As2 flux was first supplied without Mn the prior to growth, surface reconstruction disordered c(4×4), a more As-rich than c(4×4). The growth direction film grown this is [1̄100] and easy magnetization axis found be along [1̄1̄20] [110] GaAs. In contrast, when one monolayer deposited c(4×4) then grow MnAs, mainly [1̄101], [1̄10] GaAs, 90° different with respect...
This review presents the recent progress in computational materials design, experimental realization, and control methods of spinodal nanodecomposition under three- two-dimensional crystal-growth conditions spintronic materials, such as magnetically doped semiconductors. The description nanodecomposition, performed by combining first-principles calculations with kinetic Monte Carlo simulations, is discussed together extensive electron microscopy, synchrotron radiation, scanning probe, ion...
Background:Considering the high prevalence of dementia, it would be great value to develop effective tools improve cognitive function. We examined effects a human-type communication robot on function in elderly women living alone.Material/Methods:In this study, 34 healthy female volunteers alone were randomized with either or control at home for 8 weeks. The shape, voice, and motion features resemble those 3-year-old boy, while was not designed talk nod. Before 4 weeks after robot,...
Fatigue can be classified as mental and physical depending on its cause, each type of fatigue has a multi-factorial nature. We examined the effect central nervous system using electroencephalography (EEG) in eighteen healthy male volunteers.After enrollment, subjects were randomly assigned to two groups single-blinded, crossover fashion perform types fatigue-inducing experiments. Each experiment consisted four 30-min 0- or 2-back test sessions evaluation performed just before after sessions....
Spin-based electronics or spintronics is an emerging field, in which we try to utilize spin degrees of freedom as well charge transport materials and devices. While metal-based spin-devices, such magnetic-field sensors magnetoresistive random access memory using giant magnetoresistance tunneling magnetoresistance, are already put practical use, semiconductor-based has greater potential for expansion because good compatibility with existing semiconductor technology. Many devices useful...
We show high-temperature ferromagnetism in heavily Fe-doped ferromagnetic semiconductor (Ga1−x,Fex)Sb (x = 23% and 25%) thin films grown by low-temperature molecular beam epitaxy. Magnetic circular dichroism spectroscopy anomalous Hall effect measurements indicate intrinsic of these samples. The Curie temperature reaches 300 K 340 for x 25%, respectively, which are the highest values reported so far III-V semiconductors.
Abstract Magnetic Weyl semimetals have novel transport phenomena related to pairs of nodes in the band structure. Although existence fermions is expected various oxides, evidence oxide materials remains elusive. Here we show direct quantum an epitaxial 4 d ferromagnetic SrRuO 3 . We employ machine-learning-assisted molecular beam epitaxy synthesize films whose quality sufficiently high probe their intrinsic properties. Experimental observation five signatures fermions—the linear positive...