A5050999387- Magnetic properties of thin films
- Topological Materials and Phenomena
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Advanced Memory and Neural Computing
- Theoretical and Computational Physics
- Magneto-Optical Properties and Applications
- Atomic and Subatomic Physics Research
- Physics of Superconductivity and Magnetism
- Hydrogen Storage and Materials
- Graphene research and applications
- Quantum and electron transport phenomena
- Astrophysics and Cosmic Phenomena
- Ammonia Synthesis and Nitrogen Reduction
- Quantum many-body systems
- Catalysts for Methane Reforming
- Gyrotron and Vacuum Electronics Research
- Laser-Matter Interactions and Applications
- Ga2O3 and related materials
- Laser-induced spectroscopy and plasma
- Electronic and Structural Properties of Oxides
- Nanofabrication and Lithography Techniques
- Advancements in Photolithography Techniques
- Photonic and Optical Devices
- Spacecraft and Cryogenic Technologies
University of California, Los Angeles
2018-2024
Hangzhou City University
2023
Zhejiang University
2014-2022
State Key Laboratory of Modern Optical Instruments
2014-2016
Princeton University
2002
University of Minnesota
1999
Spin-momentum locked surface states in topological insulators (TIs) provide a promising route for achieving high spin-orbit torque (SOT) efficiency beyond the bulk coupling heavy metals (HMs). However, previous works, there is huge discrepancy among quantitative SOTs from TIs various systems determined by different methods. Here, we systematically study SOT TI(HM)/Ti/CoFeB/MgO same method, and make conclusive assessment of HMs. Our results demonstrate that show more than one order magnitude...
Utilizing spin-orbit torque (SOT) to switch a magnetic moment provides promising route for low-power-dissipation spintronic devices. Here, the SOT switching of nearly compensated ferrimagnet Gdx (FeCo)1-x by topological insulator [Bi2 Se3 and (BiSb)2 Te3 ] is investigated at room temperature. The current density (1.20 × 105 A cm-2 ) more than one order magnitude smaller that in conventional heavy-metal-based structures, which indicates ultrahigh efficiency charge-spin conversion (>1) surface...
The Dzyaloshinskii-Moriya interaction (DMI) is an antisymmetric exchange that stabilizes spin chirality. One scientific and technological challenge understanding controlling the between chirality electric field. In this study, we investigate unconventional field effect on interfacial DMI, skyrmion helicity, dynamics in a system with broken inversion symmetry. We design heterostructures 3d-5d atomic orbital interface to demonstrate gate bias control of DMI energy thus transform opposite...
Abstract All-electrical driven magnetization switching attracts much attention in next-generation spintronic memory and logic devices, particularly magnetic random-access (MRAM) based on the spin–orbit torque (SOT), i.e. SOT-MRAM, due to its advantages of low power consumption, fast write/read speed, improved endurance, etc. For conventional SOT-driven magnet with perpendicular anisotropy, an external assisted field is necessary break inversion symmetry magnet, which not only induces...
The topological surface states (TSS) in insulators (TIs) can exert strong spin-orbit torque (SOT) on adjacent magnetization, offering great potential implementing energy-efficient magnetic memory devices. However, there are large discrepancies among the reported spin Hall angle values TIs, and its temperature dependence still remains elusive. Here, a modulation-doped Cr-Bix Sb2-x Te3 (Cr-BST) film is quantitatively determined via both transport optic approaches, where consistent results...
Topological insulators (TI) and magnetic topological (MTI) can apply highly efficient spin-orbit torque (SOT) manipulate the magnetization with their unique surface states (TSS) ultrahigh efficiency. Here, SOT switching of a hard MTI, V-doped (Bi,Sb)
Abstract Recent advances in using topological insulators (TIs) with ferromagnets (FMs) at room temperature have opened an innovative avenue spin‐orbit torque (SOT) nonvolatile magnetic memory and low dissipation electronics. However, direct integration of TIs perpendicularly magnetized FM, while retaining extraordinary charge‐to‐spin conversion efficiency ( > 100%), remains a major challenge. In addition, the indispensable thermal compatibility modern CMOS technologies has not yet been...
Abstract The antiferromagnet (AFM) and ferromagnet (FM) interface is a unique branch of magnetics broad scientific interest. AFMs play an important role in spin‐orbit torque devices based on their ability to generate spin‐polarized current exchange bias when combined with FMs. In this study, interesting (SOT) ratchet involving the spring effect IrMn/CoFeB bilayer device perpendicular anisotropy developed. use electrical spectroscopic analysis reveals that yields unidirectional anisotropy,...
Spin-orbit torque (SOT)-MRAM is a promising candidate for future nonvolatile memory technology. Finding materials that have large SOT efficiency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\xi_{\text{DL}})$</tex> critical developing the SOT-MRAM. Topological insulators (TIs) been shown to exhibit giant xmlns:xlink="http://www.w3.org/1999/xlink">$\xi_{\text{DL}}$</tex> (>1) at room temperature. However, integration of high TIs with CoFeB...
Nanoscale spin-valve structures with a width as small 70 nm were fabricated using nanoimprint lithography and ion milling or lift off. The multilayers consisting of NiFe(10 nm)/Co(1 nm)/Cu(13 nm)/Co(10 nm)/NiFe(2 nm) deposited direct current sputtering. effects device size, well fabrication process on domain structures, switching fields, field variation, giant magnetoresistive ratio investigated scanning electron microscopy, atomic force magnetic magnetoresistance measurements.
In conventional spintronic devices, ferromagnetic materials are used, which have a magnetization dynamics timescale of around nanoseconds, setting limit for the switching speed. Increasing speed has been one major challenges research. this work we take advantage ultrafast magnetic in ferrimagnetic instead ferromagnets, and use femtosecond laser pulses plasmonic photoconductive switch to create THz electrical by spin-orbit torque. By anomalous Hall magneto-optic Kerr effect (MOKE)...
The Jinping Neutrino Experiment(JNE), conducted within the China Underground Laboratory, aims to detect and analyze of solar neutrinos, geo-neutrinos, supernova neutrinos. A one-ton prototype will soon be in commision with an upgrade from 30 channels 60 channels, which increase data bandwidth by one two orders magnitude exceed capacity current CAEN DAQ system. Additionally, enhancing performance flexibility JNE system is crucial. This paper presents design a new Tsinghua for its stability....
Antiferromagnet is a promising candidate for the next generation spintronic devices, benefiting from its ultrafast dynamics and spontaneous zero stray field. However, understanding of their spin behaviors lacking due to challenges controlling/detecting quenched net magnetization. Unconventional compensated semiconducting antiferromagnets present strong time-reversal symmetry breaking, splitting in momentum space, suitable bandgap optical control/detection. Thus, it powerful platform uncover...
To further reduce the energy consumption in spin–orbit torque devices, it is crucial to precisely quantify (SOT) different materials and structures. In this work, heavy metal/ferromagnet metal/ferrimagnet heterostructures are employed as model systems compare electrical optical methods for SOT characterization, which based on anomalous Hall effect magneto-optical Kerr effect, respectively. It found that both yield consistent strength current-driven magnetization switching measurements...
A hollow metal cone is designed to focus a laser beam into tiny highly localized spot. The finite difference time domain method has been introduced investigate the focusing effect along propagation direction. Without considering laser–plasma nonlinear interaction, numerical calculation results show that focal spot with full width at half maximum of ~0.7λ greatly enhanced intensity and depth ~3λ can be achieved. In addition, influences angle, tip size, materials, sidewall thickness incident...
Silicon-rich oxide films with controllable optical constants and properties are deposited by the reactive magnetron sputtering method on a Si target. The O/Si atomic ratio x of SiOx is tuned from 0.12 to 1.84 adjusting oxygen flow rate, which found be more effective way obtain compared changing content [O2/(Ar+O2) ratio]. can semiconductor dielectric as function x. structures components also investigated an ray photoelectron spectroscopy analysis 2p core levels, results exhibit that...
Topological insulators (TI) and magnetic topological (MTI) can apply highly efficient spin-orbit torque (SOT) manipulate the magnetization with their unique surface states ultra-high efficiency. Here, we demonstrate SOT switching of a hard MTI, V-doped (Bi,Sb)2Te3 (VBST) large coercive field that prevent influence an external field. A giant switched anomalous Hall resistance 9.2 $k\Omega$ is realized, among largest all systems. The current density be reduced to $2.8\times10^5 A/cm^2$....
In a conventional spin-valve magnetic memory cell, where nonmagnetic metal is sandwiched between two-magnetic layers, the magnetization of one layer (the pinned layer) fixed by an anti-ferromagnetic FeMn pinning layer). However, can be easily oxidized, creating instability. this paper, we demonstrate new through spontaneous formation single-domain due to nanopatterning, and layers (such as FeMn) are no longer required. Magnetic multilayer samples with NiFe(10 nm)/Co(1 nm)/Cu(13 nm)/Co(10...
Spintronics provides an efficient platform for realizing non-volatile memory and logic devices. In these systems, data is stored in the magnetization of magnetic materials, switched writing process. conventional spintronic devices, ferromagnetic materials are used which have a dynamics timescale around nanoseconds, setting limit switching speed. Increasing speed has been one challenges research. this work we take advantage ultrafast ferrimagnetic instead ferromagnets, use femtosecond laser...