A5047071565- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Magneto-Optical Properties and Applications
- Magnetic Properties and Applications
- Phase-change materials and chalcogenides
- Theoretical and Computational Physics
- Neural Networks and Reservoir Computing
- Advanced Chemical Physics Studies
- Semiconductor Quantum Structures and Devices
- Surface and Thin Film Phenomena
- Quantum optics and atomic interactions
- Magnetic Properties of Alloys
- Chemical and Physical Properties of Materials
Eindhoven University of Technology
2018-2023
The Ohio State University
2018
Utrecht University
2016-2018
University of California, Los Angeles
2018
We study current-driven skyrmion motion in uniaxial thin film antiferromagnets the presence of Dzyaloshinskii-Moriya interactions and an external magnetic field. phenomenologically include relaxation current-induced torques due to both spin-orbit coupling spatially inhomogeneous textures equation for N\'eel vector antiferromagnet. Using collective coordinate approach we apply theory a two-dimensional antiferromagnetic estimate velocity under applied DC electric current.
We present an experimental and theoretical investigation of all-optical switching by single femtosecond laser pulses. Our results demonstrate that, unlike rare earth-transition metal ferrimagnetic alloys, Pt/Co/[Ni/Co]$_N$/Gd can be switched in the absence a magnetization compensation temperature, indicative for strikingly different conditions. In order to understand underlying mechanism, we model laser-induced dynamics Co/Gd bilayers GdCo alloys on equal footing, using extension microscopic...
The mechanism responsible for the generation of optically induced spin currents upon femtosecond laser-pulse excitation ultrathin ferromagnetic layers is still a heavily debated topic. In this paper, authors study phase spin-current terahertz waves in noncollinear bilayer structures to probe Fourier space. They measure significant energy dependence spin-wave phase, which quantitatively consistent with current that proportional time derivative magnetization.
We theoretically investigate laser-induced spin transport in metallic magnetic heterostructures using an effective spin-transport description that treats itinerant electrons and thermal magnons on equal footing. Electron-magnon scattering is included taken as the driving force for ultrafast demagnetization. assume low-fluence limit, magnon system remains a quasiequilibrium, allowing transient nonzero chemical potential. In combination with diffusive equations electrons, used to chart full...
We discuss a joint microscopic theory for the laser-induced magnetization dynamics and spin transport in magnetic heterostructures based on $s\text{\ensuremath{-}}d$ interaction. Angular momentum transfer is mediated by scattering of itinerant $s$ electrons with localized ($d$ electron) spins. use corresponding rate equations focus spin-$\frac{1}{2}$ $d$ electron system, leading to simplified analytical expression local that coupled an equation nonequilibrium accumulation electrons. show...
We present a theoretical study of single-pulse all-optical switching (AOS) in synthetic-ferrimagnetic multilayers. Specifically, we investigate the role interface intermixing Co/Gd bilayers. model laser-induced magnetization dynamics bilayers using microscopic three-temperature for layered magnetic systems. Exchange scattering is included, which mediates angular momentum transfer between sublattices. In this work, each layer represented by one atomic monolayer GdCo alloy with an arbitrary Co...
All-optical switching (AOS) of magnetization by a single femtosecond laser pulse in Co/Gd based synthetic ferrimagnets is the fastest process. On other hand, He ion irradiation has become promising tool for interface engineering spintronic material platforms, giving rise to significant modification magnetic properties. In this paper, we explore use enhance AOS bilayer-based ferrimagnets. The intermixing constituent layers was both numerically simulated and experimentally verified. We...
We develop a theory for spin transport in magnetic metals that treats the contribution of magnons and electrons on equal footing. As an application we consider thermally-driven injection across interface between metal normal metal, i.e., spin-dependent Seebeck effect. show ratio magnonic electronic scales as $\sqrt{T/T_C}T_F/T_C$, with Fermi temperature $T_F$ Curie $T_C$. Since, typically, $T_C \ll T_F$, may dominate thermal injection, even though is more transparent current.
A 'toy model'-aimed at capturing the essential physics-is presented that jointly describes spin-polarized hot electron transport and spin pumping driven by local heating. These two processes both contribute to spin-current generation in laser-excited magnetic heterostructures. The model is used compare contributions directly. current modeled as one of electrons with a spin-dependent excitation relaxation scheme. Upon decay, excess energy transferred thermalized bath. elevated temperature...
Several rare-earth transition-metal ferrimagnetic systems exhibit all-optical magnetization switching upon excitation with a femtosecond laser pulse. Although this phenomenon is very promising for future opto-magnetic data storage applications, the role of non-local spin transport in these scarcely understood. Using Co/Gd and Co/Tb bilayers we isolate contribution materials to generated currents by using precessional dynamics they excite an adjacent ferromagnetic layer as probe. By measuring...
All-optical switching (AOS) of magnetization by a single femtosecond laser pulse in Co/Gd based synthetic ferrimagnets is the fastest process. On other hand, He ion irradiation has become promising tool for interface engineering spintronic material platforms, giving rise to significant modification magnetic properties. In this paper, we explore use enhance AOS bilayer-based ferrimagnets. The intermixing constituent layers was both numerically simulated and experimentally verified. We...
A `toy model' - aimed at capturing the essential physics is presented that jointly describes spin-polarized hot electron transport and spin pumping driven by local heating. These two processes both contribute to spin-current generation in laser-excited magnetic heterostructures. The model used compare contributions directly. current modeled as one of electrons with a spin-dependent excitation relaxation scheme. Upon decay, excess energy transferred thermalized bath. elevated temperature...