Yuichiro Ando
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On-chip magnon polaritons in the ultrastrong coupling regime Open
Light-matter interactions underpin the quantum technologies from quantum information processing to quantum sensing. When the coupling strength of light-matter interactions approaches the resonance frequencies of light and matter - the ultr…
Tunable Magnon Polaritons via Eddy-Current-Induced Dissipation in Metallic-Banded YIG Spheres Open
We demonstrate a robust method to dynamically tune magnon dissipation in yttrium iron garnet spheres by equipping a metallic band around the sphere's equator, enabling precise control over magnon-photon coupling states. The collective magn…
Circular photogalvanic effect in an inversion-symmetry-broken bilayer germanium nanosheet Open
Spin-to-charge conversion in monolayer and bilayer germanium(Ge) nanosheets was demonstrated via the circular photogalvanic effect (CPGE). The CPGE current generated in a spin-splitting state of the Ge nanosheet reached a maximum value whe…
Emergence of giant spin-orbit torque in a two-dimensional hole gas on the hydrogen-terminated diamond surface Open
Two-dimensional (2D) carrier systems exhibit various significant physical phenomena for electronics and spintronics, where one of the most promising traits is efficient spin-to-charge conversion stemming from their Rashba-type spin-orbit i…
Field-free superconducting diode effect in layered superconductor FeSe Open
The superconducting diode effect (SDE), where zero-resistance states appear nonreciprocally during current injection, is receiving tremendous interest in both fundamental and applied physics because the SDE is a novel manifestation of symm…
Evaluation of Spin Hall Effect in Ferromagnets by Means of Unidirectional Spin Hall Magnetoresistance in Ta/Co Bilayers Open
We investigate unidirectional spin Hall magnetoresistance (USMR) in Ta/Co bilayer systems with various Co thicknesses. A negative USMR is observed when the thickness of Co is thin due to the negative spin Hall angle of Ta, as expected from…
Magnetoresistance ratio in magnetic tunnel junction with silicon diffused MgO barrier Open
We demonstrated a magnetic tunnel junction (MTJ) consisting of Fe/MgO-Si-MgO/Fe. Si layer was deposited at room temperature and at 700 °C; when deposited at 700 °C, Si diffused into the MgO layer. The MTJ with silicon deposited at 700 °C a…
B-216 Development of a Point-of-care Multiplexed Room Temperature Stable Environmental Toxin Test Open
Background Hememics™ Biosensor System (HBS) is a platform technology enabling antigen and molecular testing in the field. The system consists of a reader, HemBox™, and a biosensing chip, HemChip™. The HemBox™ is a battery-operated, cell ph…
Gigantic Anisotropy of Self-Induced Spin-Orbit Torque in Weyl Ferromagnet Co2MnGa Open
Spin-orbit torque (SOT) is receiving tremendous attention from both fundamental and application-oriented aspects. Co2MnGa, a Weyl ferromagnet that is in a class of topological quantum materials, possesses cubic-based high structural symmet…
Gigantic Anisotropy of Self-Induced Spin-Orbit Torque in Weyl Ferromagnet Co<sub>2</sub>MnGa Open
Spin-orbit torque (SOT) is receiving tremendous attention from both fundamental and application-oriented aspects. Co2MnGa, a Weyl ferromagnet that is in a class of topological quantum materials, possesses cubic-based high structural symmet…
Multiple splitting of G-band modes from individual multiwalled carbon nanotubes Open
Surface-enhanced Raman scattering spectra of an individual multiwalled carbon nanotube (MWNT) with the innermost diameter ∼1nm, prepared by hydrogen arc discharge, show a single peak of radial breathing mode and multiple splitting of the t…
Ferroic Berry Curvature Dipole in a Topological Crystalline Insulator at Room Temperature Open
The physics related to Berry curvature is now a central research topic in condensed matter physics. The Berry curvature dipole (BCD) is a significant and intriguing condensed matter phenomenon that involves inversion symmetry breaking. How…
Modulation of Hanle magnetoresistance in an ultrathin platinum film by ionic gating Open
Hanle magnetoresistance (HMR) is a type of magnetoresistance where interplay of the spin Hall effect, Hanle-type spin precession, and spin-dependent scattering at the top/bottom surfaces in a heavy metal controls the effect. In this study,…
Anomalous sign inversion of spin-orbit torque in ferromagnetic/nonmagnetic bilayer systems due to self-induced spin-orbit torque Open
Self-induced spin-orbit torques (SI-SOTs) in ferromagnetic (FM) layers have\nbeen overlooked when estimating the spin Hall angle (SHA) of adjacent\nnonmagnetic (NM) layers. In this work, we observe anomalous sign inversion of\nthe total SO…
All‐Electric Spin Device Operation Using the Weyl Semimetal, WTe<sub>2</sub>, at Room Temperature Open
Topological quantum materials (TQMs) possess abundant and attractive spin physics, and a Weyl semimetal is the representative material because of the generation of spin polarization that is available for spin devices due to its Weyl nature…
View article: Electrical transport properties of atomically thin WSe2 using perpendicular magnetic anisotropy metal contacts
Electrical transport properties of atomically thin WSe2 using perpendicular magnetic anisotropy metal contacts Open
Tungsten diselenide, WSe2, shows excellent properties and becomes a very promising material among two-dimensional semiconductors. Wide bandgap and large spin–orbit coupling along with naturally lacking inversion symmetry in the monolayer W…
Investigation of the thermal tolerance of silicon-based lateral spin valves Open
Improvement in the thermal tolerance of Si-based spin devices is realized by employing thermally stable nonmagnetic (NM) electrodes. For Au/Ta/Al electrodes, intermixing between Al atoms and Au atoms occurs at approximately 300 °C, resulti…
View article: Approaching barrier-free contacts to monolayer MoS2 employing [Co/Pt] multilayer electrodes
Approaching barrier-free contacts to monolayer MoS2 employing [Co/Pt] multilayer electrodes Open
The broken inversion symmetry and time-reversal symmetry along with the large spin–orbit interactions in monolayer MoS 2 make it an ideal candidate for novel valleytronic applications. However, the realization of efficient spin-valley-cont…
Enhancement of low-frequency spin-orbit-torque ferromagnetic resonance signals by frequency tuning observed in Pt/Py, Pt/Co, and Pt/Fe bilayers Open
DC voltages via spin rectification effect (SRE), VDC, under microwave irradiation are investigated for three platinum (Pt)/ferromagnetic metal (FM) bilayer structures: Pt/Ni80Fe20, Pt/Co, and Pt/Fe. At the microwave frequency region lower …
Improved Thermal Tolerance of Silicon-based Lateral Spin Valves Open
Improvement in the thermal tolerance of Si-based spin devices is realized by employing thermally stable nonmagnetic (NM) electrodes. For Au/Ta/Al electrodes, intermixing between Al atoms and Au atoms occurs at approximately 300°C, resultin…
In-plane spin-orbit torque magnetization switching and its detection using the spin rectification effect at subgigahertz frequencies Open
Inplane magnetization reversal of a permalloy/platinum bilayer was detected\nusing the spin rectification effect. Using a sub GHz microwave frequency to\nexcite spin torque ferromagnetic resonance (ST FMR) in the bilayer induces two\ndiscr…
Detection of Ferromagnetic Resonance from 1 nm-thick Co Open
To explore the further possibilities of nanometer-thick ferromagnetic films (ultrathin ferromagnetic films), we investigated the ferromagnetic resonance (FMR) of 1 nm-thick Co film. Whilst an FMR signal was not observed for the Co film gro…
Enhancement of spin signals by thermal annealing in silicon-based lateral spin valves Open
The effect of thermal annealing on spin accumulation signals in silicon (Si)-based lateral spin devices is investigated. The annealing is carried out after fabrication of the spin devices, which allows us to directly compare the spin-relat…
Modulation of spin conversion in a 1.5 nm-thick Pd film by ionic gating Open
Gate-induced modulation of the spin-orbit interaction (SOI) in a 1.5 nm-thick Pd thin film grown on a ferrimagnetic insulator was investigated. Efficient charge accumulation by ionic gating enables a substantial upshift in the Fermi level …
Spin transport in a lateral spin valve with a suspended Cu channel Open
We study spin transport through a suspended Cu channel by an electrical non-local 4-terminal measurement for future spin mechanics applications. A magnetoresistance due to spin transport through the suspended Cu channel is observed, and it…
Optical visualization of the enhanced spin Hall effect in bismuth doped silicon Open
Direct visualizations of spin accumulation due to the enhanced spin Hall effect (SHE) in bismuth (Bi) - doped silicon (Si) at room temperature are realized by using helicity-dependent photovoltage (HDP) measurements. Under application of a…