A5080029294- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- ZnO doping and properties
- Graphene research and applications
- Microwave Engineering and Waveguides
- Radio Frequency Integrated Circuit Design
- Magnetic Properties and Applications
- Advanced Memory and Neural Computing
- Intermetallics and Advanced Alloy Properties
- Diamond and Carbon-based Materials Research
- Iron-based superconductors research
- GaN-based semiconductor devices and materials
- Rare-earth and actinide compounds
- Heusler alloys: electronic and magnetic properties
- Thermodynamic and Structural Properties of Metals and Alloys
- Advanced Power Amplifier Design
- Advancements in PLL and VCO Technologies
- Advanced SAR Imaging Techniques
- Quantum optics and atomic interactions
- Metallic Glasses and Amorphous Alloys
- Magneto-Optical Properties and Applications
University of Minnesota
2020-2025
Tsinghua University
2016-2020
Philips (United States)
2004
National Chung Cheng University
2004
Crystal symmetry plays an important role in the Hall effects. Unconventional spin effect (USHE), characterized by Dresselhaus and out-of-plane spins, has been observed materials with low crystal symmetry. Recently, antisymmetric planar (APHE) was discovered rutile RuO2 IrO2 (101) thin films, which also exhibit In this study, we report observation of both USHE APHE (111) using spin-torque ferromagnetic resonance harmonic measurements, respectively. Notably, unconventional efficiency from more...
Electrical control of current‐induced spin–orbit effects in magnets is supposed to reduce the power consumption high‐density memories utmost extent, but efficient metallic at a practical temperature remains elusive. Here, electrical manipulation torque investigated perpendicularly magnetized Pt/Co/HfO x heterostructures nonvolatile manner using an ionic liquid gate. The switching current magnetization can be reversibly tuned by factor two within small gate voltage range 1.5 V. modulation...
We studied the spin-to-charge and charge-to-spin conversion at room temperature in sputtered WTe2−x (x = 0.8) (t)/Co20Fe60B20(6 nm) heterostructures. Spin pumping measurements were used to characterize efficiency, spin efficiency was calculated be larger than ∼0.035. Second harmonic Hall carried out estimate ratio. found that system exhibits a large field-like torque (spin ∼0.1) small damping-like ∼0.001) compared those reported for heavy metals. High-resolution transmission electron...
Contrary to topological insulators, semimetals possess a nontrivial chiral anomaly that leads negative magnetoresistance and are hosts both conductive bulk states surface with intriguing transport properties for spintronics. Here, we fabricate highly-ordered metallic Pt3Sn Pt3SnxFe1-x thin films via sputtering technology. Systematic angular dependence (both in-plane out-of-plane) study of presents surprisingly robust quadratic linear longitudinal features Pt3SnxFe1-x, respectively. We...
Abstract Unidirectional magnetoresistance (UMR) has been observed in a variety of stacks with ferromagnetic/spin Hall material bilayer structures. In this work, UMR antiferromagnetic insulator Fe 2 O 3 /Pt structure is reported. The negative value, which related to interfacial Rashba coupling and band splitting. Thickness‐dependent measurement reveals potential competition between the unidirectional spin (USMR). This work existence insulators/heavy metal bilayers broadens way for application...
Recent advancement in the switching of perpendicular magnetic tunnel junctions with an electric field has been a milestone for realizing ultra-low energy memory and computing devices. To integrate current spin-transfer torque-magnetic junction spin–orbit devices, typical linear fJ/V m range voltage controlled anisotropy (VCMA) needs to be significantly enhanced approaches that include new materials or stack engineering. A possible bidirectional 1.1 pJ/V VCMA effect predicted by using heavily...
Mo-based perpendicular magnetic tunnel junctions (Mo-pMTJs) can outperform mainstream Ta-pMTJs in terms of anisotropy (PMA) and thermal tolerance. However, studies on the ultrafast switching Mo-pMTJ devices remain limited. In addition, although pMTJ have potential to function as cryogenic memory cells, there has been no report performance Mo-pMTJs at low temperatures until now. this Letter, were prepared with strong PMA patterned into nanoscale devices. Scanning transmission electron...
This paper describes a highly integrated CDMA 2000 US-CEL band (880-MHz) receiver. The single-chip zero-IF design incorporates all receiver signal-path functions including the low-noise amplifier (LNA) on single die. complete exceeds stringent linearity and local oscillator (LO) leakage requirements for this standard arising from coexistence with narrow-band FM signals. LNA achieves 1.0-dB noise figure +9-dBm IIP3 at high gain, by maintaining LO to antenna port well below -80 dBm gain...
We investigated temperature dependent current driven spin-orbit torques in magnetron sputtered ${\mathrm{Ru}}_{2}{\mathrm{Sn}}_{3}$ (4 and 10 nm)/${\mathrm{Co}}_{20}{\mathrm{Fe}}_{60}{\mathrm{B}}_{20}$ (5 nm) layered structures with in-plane magnetic anisotropy. The room dampinglike fieldlike spin torque efficiencies of the amorphous films were measured to be $0.14\ifmmode\pm\else\textpm\fi{}0.008\phantom{\rule{0.16em}{0ex}}(0.07\ifmmode\pm\else\textpm\fi{}0.012)$...
Unidirectional spin Hall magnetoresistance (USMR) is a effect with potential applications to read two-terminal spin–orbit-torque (SOT) devices directly. In this work, we observed large USMR value (up 0.7 × 10−11 per A/cm2, 50% larger than reported values from heavy metals) in sputtered amorphous PtSn4/CoFeB bilayers. Ta/CoFeB bilayers interfacial MgO insertion layers are deposited as control samples. The experiments show that increasing the resistance can increase value, which case...
The ternary compound ${\mathrm{Ce}}_{2}{\mathrm{PdGe}}_{6}$ exhibits antiferromagnetic ordering below the temperature $11.4\ifmmode\pm\else\textpm\fi{}0.2\mathrm{K},$ as revealed in electrical-resistivity, static magnetic susceptibility, and low-temperature specific-heat data. entropy associated with structure of was found to be close theoretical value $2R\mathrm{ln}2,$ which would expected for a doublet ground state ${\mathrm{Ce}}^{+3}$ ions ${\mathrm{Ce}}_{2}{\mathrm{PdGe}}_{6}.$...
Disordered topological insulator (TI) films have gained intense interest by benefiting from both the TI's exotic transport properties and advantage of mass production sputtering. Here, we report on clear evidence spin-charge conversion (SCC) in amorphous Gd-alloyed BixSe1–x (BSG)/CoFeB bilayers fabricated sputtering, which could be related to TI surface states. Two methods been employed study SCC BSG (tBSG = 6–16 nm)/CoFeB(5 nm) with different thicknesses. First, spin pumping is used...
We demonstrate the pumping of phonons by ferromagnetic resonance in a series ${[\mathrm{Co}(0.8\phantom{\rule{0.16em}{0ex}}\mathrm{nm})/\mathrm{Pd}(1.5\phantom{\rule{0.16em}{0ex}}\mathrm{nm})]}_{\mathrm{n}}$ multilayers ($n=6$, 11, 15, and 20) with strong magnon-phonon coupling perpendicular magnetic anisotropy. The effect is shown using broadband over range temperatures (10--300 K), where resonant damping enhancement observed at frequencies can form standing waves across multilayer....
In the course of searching for promising topological materials applications in future electronics, we evaluated spin-orbit torques (SOTs) high-quality sputtered ${\delta}-$TaN/Co20Fe60B20 devices through spin-torque ferromagnetic resonance ST-FMR and spin pumping measurements. From characterization observed a significant linewidth modulation magnetic Co20Fe60B20 layer attributed to charge-to-spin conversion generated from ${\delta}-$TaN layer. Remarkably, efficiency determined measurements...
Understanding the mechanisms of unidirectional magnetoresistance (UMR) has become an important topic for its potential application a two-terminal spin–orbit torque device. Field sweep DC measurements have been proposed and adopted to measure value UMR instead second harmonic measurements. In this paper, measurement errors in conventional are investigated. Oersted field field-like usually do not influence measurement, but large was found lead anisotropic difference when sample is perfectly...
This paper describes a highly integrated CDMA 2000 US-CEL band receiver signal path functions including the LNA on single die. The complete design exceeds stringent linearity and LO leakage requirements for this standard arising from co-existence with narrow FM signals. achieves 1.0dB noise figure +9dBm IIP3 at high gain, by maintaining to antenna port well below -80dBm all gain settings, no external is required. fabricated in 0.25/spl mu/m 40 GHz ft BICMOS technology, occupies 3mm/sup 2/.
Abstract Topological semimetal materials have attracted a great deal of attention due to their intrinsic strong spin-orbit coupling, which leads large charge-to-spin conversion efficiency and novel spin transport behaviors. In this work, we observed bilinear magnetoelectric resistance (BMER) up 0.0034 nm 2 A −1 Oe in single layer sputtered Pt 3 Sn at room temperature. Being different from previous works, the value BMER does not change out-of-plane polycrystalline nature layer. The...
Crystal symmetry plays an important role in the Hall effects. Unconventional spin effect (USHE), characterized by Dresselhaus and out-of-plane spins, has been observed materials with low crystal symmetry. Recently, antisymmetric planar (APHE) was discovered rutile RuO$_2$ IrO$_2$ (101) thin films, which also exhibit However, correlation between USHE APHE remains largely unexplored. In this study, we report observation of both (111) using spin-torque ferromagnetic resonance (ST-FMR) harmonic...
Disordered topological insulator (TI) films have gained intense interest by benefiting from both the TIs exotic transport properties and advantage of mass production sputtering. Here, we report on clear evidence spin-charge conversion (SCC) in amorphous Gd-alloyed BixSe1-x (BSG)/CoFeB bilayers fabricated sputtering, which could be related to TI surface states. Two methods been employed study SCC BSG/CoFeB(5 nm) with different BSG thicknesses. Firstly, spin pumping is used generate a current...
Contrary to topological insulators, semimetals possess a nontrivial chiral anomaly that leads negative magnetoresistance and are hosts both conductive bulk states surface with intriguing transport properties for spintronics. Here, we fabricate highly-ordered metallic Pt3Sn Pt3SnxFe1-x thin films via sputtering technology. Systematic angular dependence (both in-plane out-of-plane) study of presents surprisingly robust quadratic linear longitudinal features Pt3SnxFe1-x, respectively. We...
Topological semimetal materials have become a research hotspot due to their intrinsic strong spin-orbit coupling which leads large charge-to-spin conversion efficiency and novel transport behaviors. In this work, we observed bilinear magnetoelectric resistance (BMER) of up 0.1 nm2A-1Oe-1 in singlelayer sputtered Pt3Sn at room temperature. Different from previous observations, the value BMER does not change out-of-plane polycrystalline nature Pt3Sn. The observation provides evidence existence...
We studied the spin-to-charge and charge-to-spin conversion at room temperature in sputtered WTe2-x (x=0.8)(t)/Co20Fe60B20(6 nm) heterostructures. Spin pumping measurements were used to characterize efficiency spin was calculated be larger than ~0.035. Second harmonic Hall carried out estimate ratio. found that system exhibits a large field-like-torque (spin torque ~ 0.1) small damping-like-torque ~0.001) compared reported for heavy metals. High-resolution transmission electron microscopy...