A5066118696- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Magnetic Properties and Applications
- Advanced Memory and Neural Computing
- Magneto-Optical Properties and Applications
- Rare-earth and actinide compounds
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Ferroelectric and Negative Capacitance Devices
- Electronic and Structural Properties of Oxides
- Characterization and Applications of Magnetic Nanoparticles
- Semiconductor materials and devices
- Surface and Thin Film Phenomena
- Nuclear Materials and Properties
- Advanced Materials Characterization Techniques
- Advanced Chemical Physics Studies
- Topological Materials and Phenomena
- Iron-based superconductors research
- Inorganic Chemistry and Materials
- Advanced Data Storage Technologies
- Theoretical and Computational Physics
- Electron and X-Ray Spectroscopy Techniques
IBM Research - Almaden
2014-2025
Max Planck Institute of Microstructure Physics
2021-2025
National University of Singapore
2012-2021
Hebrew University of Jerusalem
2021
Korea University
2021
Institute of Molecular Physics of the Polish Academy of Sciences
2021
Polish Academy of Sciences
2021
University of Edinburgh
2018
IBM (United States)
2004-2015
University of California, Davis
2008
Spin-orbit torque (SOT) is an emerging technology that enables the efficient manipulation of spintronic devices. The initial processes interest in SOTs involved electric fields, spin-orbit coupling, conduction electron spins, and magnetization. More recently, has grown to include a variety other phonons, magnons, or heat. Over past decade, many materials have been explored achieve larger SOT efficiency. Recently, holistic design maximize performance devices extended material research from...
It is commonly assumed that recognition and discrimination of chirality, both in nature artificial systems, depend solely on spatial effects. However, recent studies have suggested charge redistribution chiral molecules manifests an enantiospecific preference electron spin orientation. We therefore reasoned the induced polarization may affect enantiorecognition through exchange interactions. Here we show experimentally interaction with a perpendicularly magnetized substrate enantiospecific....
Abstract The origin of spin–orbit torques, which are generated by the conversion charge-to-spin currents in non-magnetic materials, is considerable debate. One most interesting materials tungsten, for large torques have been found thin films that stabilized A15 (β-phase) structure. Here we report spin Hall angles up to approximately –0.5 incorporating oxygen into tungsten. While incorporation tungsten leads significant changes their microstructure and electrical resistivity, measured be...
There has been considerable interest in spin-orbit torques for the purpose of manipulating magnetization ferromagnetic elements spintronic technologies. Spin-orbit are derived from spin currents created charge materials with significant coupling that propagate into an adjacent material. A key challenge is to identify exhibit large Hall angles, is, efficient charge-to-spin current conversion. Using torque resonance, we report observation a giant angle [Formula: see text] up ~0.35...
Abstract Ferromagnets are commonly magnetized by either external magnetic fields or spin polarized currents. The manipulation of magnetization spin-current occurs through the spin-transfer-torque effect, which is applied, for example, in modern magnetoresistive random access memory. However, current density required spin-transfer torque order 1 × 10 6 A·cm −2 , about 25 electrons s −1 cm . This relatively high significantly affects devices’ structure and performance. Here we demonstrate...
We observe edge transport in the topologically insulating InAs/GaSb system disordered regime. Using asymmetric current paths we show that conduction occurs exclusively along device edge, exhibiting a large Hall signal at zero magnetic fields, while for symmetric paths, conductance between two mesoscopicly separated probes is quantized to 2e2/h. Both and self-averaged resilience are temperature independent temperatures 20 mK 1 K.
We use single-cycle THz fields and the femtosecond magneto-optical Kerr effect to, respectively, excite probe magnetization dynamics in two thin-film ferromagnets with different lattice structures: crystalline Fe amorphous CoFeB. observe Landau-Lifshitz-torque of comparable magnitude both systems, but only sample shows ultrafast demagnetization caused by spin-lattice depolarization THz-induced spin current. Quantitative modeling that such scattering events occur on similar time scales than...
Kerr microscopy is used to investigate domain wall motion in response nanosecond-long current pulses perpendicularly magnetized micron-sized Co/Ni/Co racetracks. Domain velocities greater than 300 m/s are observed. The velocity independent of the pulse length for a wide range densities. However, dynamics depends on just above threshold motion, where slow creep occurs, and at very high densities, nucleation takes place. We also observe tilting that cannot be accounted by Oersted field from...
Highly efficient current-induced motion of chiral domain walls was recently demonstrated in synthetic antiferromagnetic (SAF) structures due to an exchange coupling torque (ECT). The ECT derives from the through a ruthenium spacer layer between two perpendicularly magnetized layers that comprise SAF. Here we report same mechanism applies ferrimagnetic bi-layers formed adjacent Co and Gd layers. In particular, show is maximized at temperature TA where angular momenta balance each other,...
The Gilbert damping of ferromagnetic materials is arguably the most important but least understood phenomenological parameter that dictates real-time magnetization dynamics. Understanding physical origin highly relevant to developing future fast switching spintronics devices such as magnetic sensors and random access memory. Here, we report an experimental study temperature-dependent in permalloy (Py) thin films varying thicknesses by resonance. From thickness dependence, two independent...
The current-induced spin-orbit torque switching of ferromagnets has had huge impact in spintronics. However, short spin-diffusion lengths limit the thickness switchable ferromagnetic layers, thereby limiting their thermal stability. Here, we report a previously unobserved seeded (SSOT) by which current can set magnetic states even thick layers chiral kagome antiferromagnet Mn3Sn. mechanism involves setting orientation antiferromagnetic domains thin region at interface with spin currents...
The generation of spin currents and their application to the manipulation magnetic states is fundamental spintronics. Of particular interest are chiral antiferromagnets that exhibit properties typical ferromagnetic materials even though they have negligible magnetization. Here, we report a robust current with both in-plane out-of-plane polarization in epitaxial thin films antiferromagnet Mn3Sn proximity permalloy layers. By employing temperature-dependent spin-torque resonance, find...
Tunneling anisotropic magnetoresistance (TAMR) is observed in tunnel junctions with transition metal electrodes as the moments are rotated from in-plane to out-of-plane sufficiently large magnetic fields that nearly parallel one another. A complex angular dependence of tunneling resistance found twofold and fourfold components vary strongly bias voltage. Distinctly different TAMR behaviors obtained for devices formed highly textured crystalline MgO(001) amorphous...
We investigate the intrinsic Gilbert damping constant in perpendicular magnetic anisotropy Co/Ni multilayer system by means of an all-optical method. find that does not depend on stack number and when field is high enough. In contrast, extrinsic strongly correlated with inhomogeneous distribution low-field regime, as observed magneto-optical images. Intriguingly, consistently reduced decreasing length scale measurements, providing a concrete to determine damping.
Spin-polarized charge currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer torque (STT). Recently, taking advantage the spin-dependent thermoelectric properties materials, novel means generating spin from temperature gradients, and their associated thermal-spin torques (TSTs), have been proposed, but so far these TSTs not large enough to influence MTJ switching. Here we demonstrate significant in MTJs gradients across ultrathin MgO barriers that considerably...
Chirality, handedness, is one of the most fundamental intriguing asymmetries in nature. By definition, chiral objects cannot be superimposed onto each other after mirror reflection operation. Numerous examples structures can found nature, for example, molecules and magnetic nanostructures. Moving electrons are associated with handedness by their own spins due to spin-orbit interaction thus exhibiting various emergent phenomena as they interact materials, which otherwise would not observed...