A5007603168- Magnetic properties of thin films
- Magneto-Optical Properties and Applications
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Advanced Condensed Matter Physics
- Magnetic Field Sensors Techniques
- Graphene research and applications
- Theoretical and Computational Physics
- Magnetic Properties and Applications
- Physics of Superconductivity and Magnetism
- Characterization and Applications of Magnetic Nanoparticles
- Quantum many-body systems
- Multiferroics and related materials
- Magnetic and transport properties of perovskites and related materials
- Crystal Structures and Properties
- 2D Materials and Applications
- Optical Systems and Laser Technology
- Plasmonic and Surface Plasmon Research
- High Entropy Alloys Studies
- Surface and Thin Film Phenomena
- Microstructure and Mechanical Properties of Steels
- Iron-based superconductors research
- Orbital Angular Momentum in Optics
- Advanced Memory and Neural Computing
- Gold and Silver Nanoparticles Synthesis and Applications
Guangdong Institute of New Materials
2020
Guangdong Academy of Sciences
2020
University of California, Riverside
2013-2019
Pennsylvania State University
2019
Research Center for Applied Science, Academia Sinica
2019
Institute of Atomic and Molecular Sciences, Academia Sinica
2019
National Taiwan University
2019
National Synchrotron Radiation Research Center
2019
National Institute for Materials Science
2017
The Ohio State University
2017
We demonstrate the anomalous Hall effect (AHE) in single-layer graphene exchange coupled to an atomically flat yttrium iron garnet (YIG) ferromagnetic thin film. The conductance has magnitude of ∼0.09(2e2/h) at low temperatures and is measurable up ∼300 K. Our observations indicate not only proximity-induced ferromagnetism graphene/YIG with a large interaction, but also enhanced spin-orbit coupling that believed be inherently weak ideal graphene. order can lead novel transport phenomena such...
Topological surface states reveal proximity-induced ferromagnetism with perpendicular anisotropy persisting above 400 K.
The Dzyaloshinskii-Moriya interaction (DMI) at the heavy metal (HM) and ferromagnetic (FM) interface has been recognized as a key ingredient in spintronic applications. Here we investigate chemical trend of DMI on 5d band filling (5d^{3}-5d^{10}) HM element HM/FM (FM=CoFeB,Co)/MgO multilayer thin films. is quantitatively evaluated by measuring asymmetric spin wave dispersion using Brillouin light scattering. Sign reversal 20 times modification coefficient D have measured varied. can be...
The quantum anomalous Hall effect (QAHE) has been recently demonstrated in Cr- and V-doped three-dimensional topological insulators (TIs) at temperatures below 100 mK. In those materials, the spins of unfilled d-electrons transition metal dopants are exchange coupled to develop a long-range ferromagnetic order, which is essential for realizing QAHE. However, addition random does not only introduce excess charge carriers that require readjusting Bi/Sb ratio, but also unavoidably introduces...
We demonstrate robust interface strain-induced perpendicular magnetic anisotropy in atomically flat ferrimagnetic insulator Tm3Fe5O12 films grown with pulsed laser deposition on substituted-Gd3Ga5O12 substrate which maximizes the tensile strain at interface. In bilayers consisting of Pt and TIG, we observe large squared Hall hysteresis loops over a wide range thicknesses room temperature. When thin Cu layer is inserted between magnitude decays but stays finite as thickness increases up to 5...
Pure spin current, a flow of angular momentum without any companying net charge, is generated in two common ways. One makes use the Hall effect normal metals (NM) with strong spin-orbit coupling, such as Pt or Ta. The other utilizes collective motion magnetic moments waves quasi-particle excitations called magnons. A popular material for latter yttrium iron garnet, insulator (MI). Here we demonstrate NM/MI/NM trilayers that these types currents are interconvertible across interfaces,...
By using gold nanorods as an example, we report the dynamic and reversible tuning of plasmonic property anisotropically shaped colloidal metal nanostructures by controlling their orientation external magnetic fields. The orientational control enables instant selective excitation plasmon modes AuNRs through manipulation field direction relative to directions incidence polarization light.
Abstract Spin-momentum locking in protected surface states enables efficient electrical detection of magnon decay at a magnetic-insulator/topological-insulator heterojunction. Here we demonstrate this property using the spin Seebeck effect (SSE), that is, measuring transverse thermoelectric response to temperature gradient across thin film yttrium iron garnet, an insulating ferrimagnet, and forming heterojunction with (Bi x Sb 1− ) 2 Te 3 , topological insulator. The non-equilibrium...
In bilayers consisting of Pd and yttrium iron garnet (Y(3)Fe(5)O(12) or YIG), we observe vanishingly small room-temperature conventional anisotropic magnetoresistance but large new that is similar to the spin Hall previously reported in Pt-YIG bilayers. We report a temperature dependence study two effects As decreased, shows peak, whereas effect starts appear increases monotonically. find peak shifts lower temperatures thicker samples, feature characteristic current effect. The distinct...
The anisotropic magnetoresistance (AMR) of ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$ (CGT), a layered ferromagnetic insulator, is investigated under an applied hydrostatic pressure up to 2 GPa. easy-axis direction the magnetization inferred from AMR saturation feature in presence and absence pressure. At zero pressure, easy axis along $c$ or perpendicular layer. Upon application > 1 GPa, uniaxial anisotropy switches easy-plane which drives equilibrium $ab$ plane at magnetic...
A layer-by-layer epitaxial growth up to 227 atomic layers of ferrimagnetic insulator yttrium iron garnet (YIG) thin films is achieved on (110)-oriented gadolinium gallium substrates using pulsed laser deposition. Atomically smooth terraces are observed YIG 100 nm in thickness. The root-mean-square roughness as low 0.067 nm. easy-axis lies the film plane, indicating dominance shape anisotropy. For (110)-YIG films, there well-defined two-fold in-plane anisotropy, with easiest axis directed...
Abstract Magnetic insulators (MIs) attract tremendous interest for spintronic applications due to low Gilbert damping and the absence of Ohmic loss. Spin-orbit torques (SOTs) on MIs are more intriguing than magnetic metals since SOTs cannot be transferred through direct injection electron spins. Understanding remains elusive, especially how scale with MI film thickness. Here, we observe critical role dimensionality SOT efficiency by studying layer thickness-dependent in tungsten/thulium iron...
The spontaneously broken time reversal symmetry can lead to the formation of an energy gap in Dirac spectrum surface states a topological insulator (TI) which consequently give rise variety interesting phenomena potentially useful for spintronics. In this work, we couple non-magnetic TI high Curie temperature TC magnetic induce strong exchange interaction via proximity effect. We have successfully grown 5 quintuple layer thick ternary (BixSb1-x)2Te3 films on atomically flat yttrium iron...
We use temperature-dependent Hall measurements to identify contributions of spin Hall, magnetic proximity, and sublattice effects the anomalous signal in heavy metal/ferrimagnetic insulator heterostructures with perpendicular anisotropy. This approach enables detection both proximity effect onset temperature magnetization compensation provides essential information regarding interfacial exchange coupling. Onset a yields local extremum signal, which occurs at higher as thickness increases....
Ultra-high strength maraging stainless steels possess many important applications such as in aircraft landing gears owing to their excellent and good process ability. However, traditional ultra-high are facing the challenge of balancing ductility while pursuing strength. This is mainly due semi-coherent or non-coherent relationship between precipitated nanoparticles body-centered cubic (BCC) martensitic matrix. In this work, a novel steel (Fe-7.95Cr-13.47Ni-3.10Al-1.83Mo-0.03C-0.23Nb, weight...
Bilayers of 20 quintuple layer Bi2Se3 on 30 nm thick yttrium iron garnet (YIG) have been grown with molecular beam epitaxy in conjunction pulsed laser deposition. The presence the ferri-magnetic insulator YIG causes additional scattering to surface states topological layer, as indicated by temperature dependence resistivity. From two-channel analysis Hall data, we find that contribution bilayer samples is greatly reduced. Furthermore, weak antilocalization effect from clearly suppressed due layer.
Quantum anomalous Hall state is expected to emerge in Dirac electron systems such as graphene under both sufficiently strong exchange and spin-orbit interactions. In pristine graphene, neither interaction exists; however, interactions can be acquired by coupling a magnetic insulator revealed the effect. Here, we show enhanced proximity sandwiching between ferrimagnetic yttrium iron garnet (YIG) hexagonal-boron nitride (h-BN) which also serves top gate dielectric. By sweeping top-gate...
Spin dynamics of magnetic insulator is markedly modulated by the Dirac surface states in adjacent topological insulator.
We present a synthesis/processing method for fabricating ferrimagnetic insulator (Bi-doped yttrium iron garnet) thin films with tunable magnetic anisotropy. Since the desired properties rely on controllable thickness and successful doping, we pay attention to entire procedure (nanopowder synthesis, nanocrystalline target preparation pulsed laser deposition (PLD)). Atomically flat were deposited by PLD (111)-orientated aluminum garnet. show significant enhancement of perpendicular anisotropy...
30-80 nm thick yttrium iron garnet (YIG) films are grown by pulsed laser deposition on a 5 sputtered Pt atop gadolinium gallium substrate (GGG) (110). Upon post-growth rapid thermal annealing, single crystal YIG(110) emerges as if it were epitaxially GGG(110) despite the presence of intermediate film. The YIG surface shows atomic steps with root-mean-square roughness 0.12 flat terraces. Both Pt/YIG and GGG/Pt interfaces atomically sharp. resulting show clear in-plane uniaxial magnetic...
As a thin layer of palladium (Pd) is directly deposited on an yttrium iron garnet or YIG (Y3Fe5O12) magnetic insulator film, Pd develops both low- and high-field magneto-transport effects that are absent in standalone thick YIG. While the low-field magnetoresistance peak tracks coercive field much larger Hall effect do not show any obvious relationship with bulk magnetization. The distinct shown to be caused by interfacial local moments Pd.
Electrical currents in a magnetic-insulator/heavy-metal heterostructure can induce two simultaneous effects, namely, spin Hall magnetoresistance (SMR) on the heavy-metal side and spin-orbit torques (SOTs) magnetic-insulator side. Within framework of pure current model based bulk effect (SHE), ratio Hall-induced anomalous (SH-AHE) to SMR should be equal fieldlike torque (FLT) dampinglike (DLT). We perform quantitative study SMR, SH-AHE, SOTs series thulium iron garnet/platinum or...
As a non-magnetic heavy metal is attached to ferromagnet, vertically flowing heat-driven spin current converted transverse electric voltage, which known as the longitudinal Seebeck effect (SSE). If ferromagnet metal, this voltage also accompanied by voltages from two other sources, i.e., anomalous Nernst in both and proximity-induced ferromagnetic boundary layer. By properly identifying carefully separating those different effects, we find that pure circuit additional drawn generates another...