Colossal Orbital Current Induced by Gradient Oxidation for High-Efficiency Magnetization Switching.

Orbital angular momentum flow can be used to develop a low-dissipation electronic information device by manipulating the orbital current. However, efficiently generating and fully harnessing orbital currents is a formidable challenge. In this study, an approach is presented that induces a colossal orbital current by gradient oxidation in Pt/Ta to enhance spin-orbit torque (SOT) and achieve high-efficiency magnetization switching.

Enhanced Spin-Orbit Torque Efficiency in Platinum-Gadolinium Oxide Nanocomposite Films.

Spin-orbit torque (SOT) has emerged as an effective means of manipulating magnetization. However, the current energy efficiency of SOT operation is inefficient due to low damping-like SOT efficiency per unit current bias. In this work, we dope conventional rare earth oxides, GdO, into highly conductive platinum by magnetron sputtering to form a new group of spin Hall materials.

Splitting phenomenon of ferromagnetic resonance spectra in NiFe films deposited on periodically rippled sapphire substrates.

The splitting phenomenon of ferromagnetic resonance (FMR) spectra of NiFe(NiFe) films deposited on periodically rippled sapphire substrates is studied experimentally with the help of micromagnetic simulation. The analyses show that the splitting of FMR spectra is related to the periodic ripple topography of films. When the applied magnetic field is perpendicular to the ripple direction, the effective field of periodically rippled films becomes inhomogeneous.

Structural and magnetic properties of Y(GaAlFe)O liquid-phase epitaxy films with low ferromagnetic resonance losses.

Ultra-thin rare earth iron garnet (RIG) films with a narrow ferromagnetic resonance (FMR) line width and a low damping factor have attracted a great deal of attention for microwave and spintronic applications. In this work, 200 nm Y(GaAlFe)O garnet (GaAl-YIG) films were prepared on gadolinium gallium garnet (GGG) substrates by liquid-phase epitaxy (LPE) with low saturation magnetization. The microstructural properties, chemical composition, and magnetostatic and dynamic magnetization characteristics of the films are discussed in detail.

Giant Extrinsic Spin Hall Effect in Platinum-Titanium Oxide Nanocomposite Films.

Although the spin Hall effect provides a pathway for efficient and fast current-induced manipulation of magnetization, application of spin-orbit torque magnetic random access memory with low power dissipation is still limited to spin Hall materials with low spin Hall angles or very high resistivities. This work reports a group of spin Hall materials, Pt (TiO ) nanocomposites, that combines a giant spin Hall effect with a low resistivity. The spin Hall angle of Pt (TiO ) in an yttrium iron garnet/Pt (TiO ) double-layer heterostructure is estimated from a combination of ferromagnetic resonance, spin pumping, and inverse spin Hall experiments.

High-Performance Multifunctional Photodetector and THz Modulator Based on Graphene/TiO/p-Si Heterojunction.

In this paper, we have reported a multifunctional device from graphene/TiO/p-Si heterojunction, followed by its systematical analysis of optical response in a device under ultraviolet-visible-infrared band and transmission changes of terahertz waves in the 0.3-1.0 THz band under different bias voltages.

Effect of Interfacial Roughness Spin Scattering on the Spin Current Transport in YIG/NiO/Pt Heterostructures.

Interfacial properties play a vital role in spin current injection from the ferromagnetic (FM) layer into the nonmagnetic (NM) layer. So far, impedance matching and spin-orbit coupling are two important, well-known factors in spin current transport in FM/NM heterostructures. In this work, the spin current transport in YFeO (YIG)/NiO/Pt heterostructures was investigated by spin Hall magnetoresistance and inverse spin Hall effect measurements.

High-Performance All-Optical Terahertz Modulator Based on Graphene/TiO/Si Trilayer Heterojunctions.

In this paper, we demonstrate a trilayer hybrid terahertz (THz) modulator made by combining a p-type silicon (p-Si) substrate, TiO interlayer, and single-layer graphene. The interface between Si and TiO introduced a built-in electric field, which drove the photoelectrons from Si to TiO, and then the electrons injected into the graphene layer, causing the Fermi level of graphene to shift into a higher conduction band. The conductivity of graphene would increase, resulting in the decrease of transmitted terahertz wave.

Reconfigurable nanoscale spin-wave directional coupler using spin-orbit torque.

We present a reconfigurable nanoscale spin-wave directional coupler based on spin-orbit torque (SOT). By micromagnetic simulations, it is demonstrated that the functionality and operating frequency of proposed device can be dynamically switched by inverting the whole or part of the relative magnetic configuration of the dipolar-coupled waveguides using SOT. Utilizing the effect of sudden change in coupling length, the functionality of power divider can be realized.

Preparation and Optical Properties of GeBi Films by Using Molecular Beam Epitaxy Method.

Ge-based alloys have drawn great interest as promising materials for their superior visible to infrared photoelectric performances. In this study, we report the preparation and optical properties of germanium-bismuth (GeBi) thin films by using molecular beam epitaxy (MBE). GeBi thin films belong to the n-type conductivity semiconductors, which have been rarely reported.

Infrared Properties and Terahertz Wave Modulation of Graphene/MnZn Ferrite/p-Si Heterojunctions.

MnZn ferrite thin films were deposited on p-Si substrate and used as the dielectric layer in the graphene field effect transistor for infrared and terahertz device applications. The conditions for MnZn ferrite thin film deposition were optimized before device fabrication. The infrared properties and terahertz wave modulation were studied at different gate voltage.

Manipulate the magnetic anisotropy of nanoparticle assemblies in arrays.

Tuning the magnetic anisotropy of nanoparticle assemblies is critical for their applications such as on-chip magnetic electronic components and electromagnetic wave absorption. In this work, we developed a facile hierarchical self-assembly method to separately control the magnetic shape and magnetocrystalline anistropy of individual nanoparticle assemblies in arrays. Since magnetic nanoparticle assemblies in the array have the same size, shape and alignment, we are able to study the magnetic properties of individual nanoparticle assembly by measuring the whole arrays.

Large area Germanium Tin nanometer optical film coatings on highly flexible aluminum substrates.

Germanium Tin (GeSn) films have drawn great interest for their visible and near-infrared optoelectronics properties. Here, we demonstrate large area Germanium Tin nanometer thin films grown on highly flexible aluminum foil substrates using low-temperature molecular beam epitaxy (MBE). Ultra-thin (10-180 nm) GeSn film-coated aluminum foils display a wide color spectra with an absorption wavelength ranging from 400-1800 nm due to its strong optical interference effect.