A5058913031- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Magneto-Optical Properties and Applications
- Magnetic Properties and Applications
- Advanced Memory and Neural Computing
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Magnetic Field Sensors Techniques
- Molecular Junctions and Nanostructures
- Semiconductor materials and devices
- Congenital Heart Disease Studies
- Theoretical and Computational Physics
- Thermal properties of materials
- Heat Transfer and Optimization
- Neonatal Respiratory Health Research
- Pulmonary Hypertension Research and Treatments
- Gastrointestinal disorders and treatments
- Transition Metal Oxide Nanomaterials
- Thermal Radiation and Cooling Technologies
- Copper Interconnects and Reliability
- Complex Systems and Time Series Analysis
- Ferroelectric and Negative Capacitance Devices
- Time Series Analysis and Forecasting
- Pancreatic and Hepatic Oncology Research
National Institute of Advanced Industrial Science and Technology
2022-2024
Tohoku University
2009-2021
Spintronics Research Network of Japan
2013-2021
National Institute for Materials Science
2019-2021
The University of Tokyo
2019-2021
Japan Science and Technology Agency
2011-2021
Keio University
2009-2018
Institute for Materials Research, Tohoku University
2010-2014
RIKEN
2000
We report anisotropic magnetoresistance in $\mathrm{Pt}|{\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ bilayers. In spite of ${\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ being a very good electrical insulator, the resistance Pt layer reflects its magnetization direction. The effect persists even when Cu is inserted between and ${\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$, excluding contribution induced equilibrium at interface. Instead, we show that originates from...
We present a theory of the spin Hall magnetoresistance (SMR) in multilayers made from an insulating ferromagnet F, such as yttrium iron garnet (YIG), and normal metal N with spin-orbit interactions, platinum (Pt). The SMR is induced by simultaneous action inverse effects therefore non-equilibrium proximity phenomenon. compute F$|$N F$|$N$|$F layered systems, treating spin-diffusion quantum mechanical boundary conditions at interfaces terms spin-mixing conductance. Our results explain...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Ken-ichi Uchida, Hiroto Adachi, Takeru Ota, Hiroyasu Nakayama, Sadamichi Maekawa, Eiji Saitoh; Observation of longitudinal spin-Seebeck effect in magnetic insulators. Appl. Phys. Lett. 25 October 2010; 97 (17): 172505. https://doi.org/10.1063/1.3507386 Download citation file: Ris (Zotero) Reference Manager...
The inverse spin-Hall effect (ISHE) induced by the spin pumping has been investigated systematically in simple ferromagnetic/paramagnetic bilayer systems. driven ferromagnetic resonance injects a current into paramagnetic layer, which gives rise to an electromotive force transverse using ISHE layer. In Ni81Fe19/Pt film, we found perpendicular applied magnetic field at condition. spectral shape of is well reproduced Lorentz function, indicating that due pumping; extrinsic magnetogalvanic...
We experimentally investigate and quantitatively analyze the spin Hall magnetoresistance effect in ferromagnetic insulator/platinum insulator/nonferromagnetic metal/platinum hybrid structures. For insulator, we use either yttrium iron garnet, nickel ferrite, or magnetite for nonferromagnet, copper gold. The is theoretically ascribed to combined action of inverse platinum metal top layer. It therefore should characteristically depend upon orientation magnetization adjacent ferromagnet prevail...
This Letter provides evidence for intrinsic longitudinal spin Seebeck effects (LSSEs) that are free from the anomalous Nernst effect (ANE) caused by an extrinsic proximity effect. We report observation of LSSEs in $\mathrm{Au}/{\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ (YIG) and Pt/Cu/YIG systems, showing LSSE appears even when mechanism ANE is clearly removed. In conventional Pt/YIG structure, furthermore, we separate comparing voltages different magnetization temperature-gradient...
Geometric effects on the inverse spin Hall effect (ISHE) induced by pumping driven ferromagnetic resonance (FMR) have been investigated quantitatively. We measured FMR spectra and electromotive force ISHE with changing size thickness in Ni${}_{81}$Fe${}_{19}$/Pt films. The intensity of generated charge currents due to changes systematically film geometry, which is consistent prediction ISHE. experimental results show a clear difference between Ni${}_{81}$Fe${}_{19}$ Pt dependence pumping....
We report the observation of magnetoresistance originating from Rashba spin-orbit coupling (SOC) in a metallic heterostructure: Rashba-Edelstein (RE) magnetoresistance. show that simultaneous action direct and inverse RE effects $\mathrm{Bi}/\mathrm{Ag}/\mathrm{CoFeB}$ trilayer couples current-induced spin accumulation to electric resistance. The resistance changes with magnetic-field angle, reminiscent Hall magnetoresistance, despite fact bulk SOC is not responsible for further found that,...
A platinum (Pt)/yttrium iron garnet (YIG) bilayer system with a well-controlled interface has been developed; spin mixing conductance at the Pt/YIG studied. clear good crystal perfection is experimentally demonstrated to be one of important factors for an ultimate conductance. The obtained 1.3 × 1018 m–2 interface, which close theoretical prediction.
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Dazhi Hou, Z. Qiu, K. Harii, Y. Kajiwara, Uchida, Fujikawa, H. Nakayama, T. Yoshino, An, Ando, Xiaofeng Jin, E. Saitoh; Interface induced inverse spin Hall effect in bismuth/permalloy bilayer. Appl. Phys. Lett. 23 July 2012; 101 (4): 042403. https://doi.org/10.1063/1.4738786 Download citation file: Ris (Zotero)...
We review the recently discovered spin Hall magnetoresistance (SMR) and related effects from a theoretical point of view. The SMR is observed in bilayers magnetic insulator metal, which currents aregenerated normal metal due to effect. associated angular momentum transfer ferromagnetic layer thereby electrical resistance modulated by angle between applied current magnetization direction. provides convenient tool non-invasively measure direction spin-transfer torque an insulator. introduce...
We report temperature evolution of spin-charge conversion through the inverse Rashba-Edelstein effect (IREE) in a metallic heterostructure. The IREE was induced Ag/Bi junction by spin pumping, dynamical injection from ferromagnetic metal; nonequilibrium accumulation created is converted into charge current at interface. By measuring arising different temperatures, we found that efficiency almost independent temperature. This method offers versatile route for probing spin-orbit coupling...
We have investigated the anomalous Nernst effect (ANE) in $\mathrm{F}{\mathrm{e}}_{1\ensuremath{-}x}\mathrm{G}{\mathrm{a}}_{x}$ alloy films with different Ga atomic compositions ($x=0\ensuremath{-}0.44$) deposited on MgO(001) single-crystalline substrates. found that magnitude of ANE increases increasing $x$ up to $x=0.32$ even though saturation magnetization decreases $x$, suggesting a dominant contribution intrinsic mechanism observed ANE. The reaches...
Thermal switching provides an effective way for active heat flow control, which has recently attracted increasing attention in terms of nanoscale thermal management technologies. In magnetic and spintronic materials, the conductivity depends on magnetization configuration: this is magneto-thermal resistance effect. Here we show that epitaxial Cu/Co$_{50}$Fe$_{50}$ multilayer film exhibits giant magnetic-field-induced modulation cross-plane conductivity. The ratio reaches 150% at room...
The frequency dependence of magnetization precession in spin pumping has been investigated using the inverse spin-Hall effect a Pt/Y3Fe5O12 bilayer film. We found that magnitude current generated by depends weakly on applied microwave frequency. This weak dependence, which is attributed to compensation between change spin-pumping cycle and dynamic magnetic susceptibility, favorable for making spin-current-driven demodulator. behavior consistent with model calculation based...
We have investigated the voltage-controlled magnetic anisotropy (VCMA) effect in Co/MgO junctions by inserting a sub-atomic layer of heavy metals at interface. evaluated an electrical control using micro-magneto-optical Kerr magnetometer. The VCMA coefficient increases with insertion Ir or Pt and decreases Os layer. These results imply that can be engineered doping interface engineering metal provides us method to over wide range.
Electroresistance effect was detected in a metallic thin film using ionic-liquid-gated electric-double-layer transistors (EDLTs). We observed reversible modulation of the electric resistance Au film. In this system, we found that an double layer works as nanogap capacitor with 27 (-25) MV cm-1 field by applying only 1.7 V positive (negative) gate voltage. The experimental results indicate EDLT technique can be used for controlling surface electronic states on systems.
We show a clear guideline for generating large spin current using the pumping in metallic bilayer films. measured currents generated by Ni1−xFex/Pt films inverse spin-Hall effect (ISHE). The magnitude of ISHE signals are well reproduced calculation based on model pumping. result shows that amplitude is universally determined product saturation magnetization, additional damping constant, and solid angle magnetization precession.
Researchers report the discovery of a way for molecular engineering Rashba spin-orbit devices.
The voltage-controlled magnetic anisotropy (VCMA) effect has been proposed as an energy efficient approach for controlling the direction of magnetization. To demonstrate scalability a magnetoresistive random access memory, we need to optimize perpendicular (PMA), tunnel magnetoresistance (TMR), and VCMA properties. Here, performed systematic investigation effects inserting post-oxidized MgAl layer on PMA, TMR, in epitaxial junctions (MTJs). PMA TMR have substantial dependences thickness...
The spin-Seebeck effect (SSE) converts a temperature gradient into spin voltage, driving force for nonequilibrium currents, in ferromagnetic metal. In this study, the SSE Ni81Fe19, Ni, and Fe films has been investigated by means of inverse spin-Hall (ISHE) Pt at room temperature. ISHE allows us to detect signals as electric voltage separated from extrinsic thermoelectric effects. experimental results show that sign thermally induced due is reversed between higher- lower-temperature ends...
Using a Pt/Y3Fe5O12 (YIG) hybrid structure attached to piezoelectric actuator, we demonstrate the generation of spin currents from sound waves. This “acoustic pumping” (ASP) is caused by wave generated which then modulates distribution function magnons in YIG layer and results pure-spin-current injection into Pt across Pt/YIG interface. In layer, this injected current converted an electric voltage due inverse spin-Hall effect (ISHE). The ISHE induced ASP detected measuring at resonance...
The inverse spin-Hall effect, conversion of spin currents into electromotive force, has been investigated in Pt thin films with changing the thickness films. We measured electric voltage due to effect induced by pumping Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">81</sub> Fe xmlns:xlink="http://www.w3.org/1999/xlink">19</sub> /Pt bilayer systems different ( <i xmlns:xlink="http://www.w3.org/1999/xlink">d</i>...
We have studied magnetoresistance and Hall effects for 1.8-nm-thick Pt films grown on a ferrimagnetic insulator Y3Fe5O12 in wide temperature (0.46-300 K) magnetic-field (-15-15 T) region. In the low-temperature regime where quantum corrections to conductivity are observed, weak antilocalization behavior observed is critically suppressed when film attached Y3Fe5O12. resistance also affected by Y3Fe5O12, it exhibits logarithmic dependence broad range. The magnetotransport properties high-field...