Related papers: Ultrafast demagnetization in bulk vs thin films: a…
The spin dynamics in Ni is studied by an exact diagonalization method on the ultrafast time scale. It is shown that the femtosecond relaxation of the magneto-optical response results from exchange interaction and spin-orbit coupling. Each…
We explore the impact of optical excitation using two interfering ultrashort optical pulses on ultrafast magnetization dynamics. Our investigation focuses on Pt/Co/Pt multilayers and TbCo alloy samples, employing a dual pump approach. We…
By correlating time- and angle-resolved photoemission and time-resolved transverse- magneto- optical Kerr effect measurements, both at extreme ultraviolet wavelengths, we uncover the universal nature of the ultrafast photoinduced magnetic…
A multiscale studying integrating ab initio quantum mechanics, classical molecular dynamics and two-temperature model, is carried out to study film thickness dependent femtosecond laser spallation and ablation. As an interval of 130.73 nm,…
We report measurement of a spin pumping effect due to fluctuations of the magnetic order of IrMn thin films. A precessing NiFe ferromagnet injected spins into IrMn spin sinks, and enhanced damping was observed around the IrMn magnetic phase…
We have studied magnetism in Ti_[1-x]Co_xO_[2-\delta] thin films with various x and \delta by soft x-ray magnetic circular dichroism (XMCD) measurements at the Co L_[2,3] absorption edges. The estimated ferromagnetic moment by XMCD was…
Exact calculated time evolutions in the framework of a many-electron model of itinerant magnetism provide new insights into the laser-induced ultrafast demagnetization observed in ferromagnetic (FM) transition metal thin films. The…
Understanding spin dynamics on femto- and picosecond timescales offers new opportunities for faster and more efficient spintronic devices. Here, we experimentally investigate the coherent spin dynamics after ultrashort laser excitation by…
We study ultrafast magnetization quenching of ferromagnetic iron following excitation by an optical vs a terahertz pump pulse. While the optical pump (photon energy of 3.1 eV) induces a strongly nonthermal electron distribution, terahertz…
Theoretical calculations, computer simulations and experiments indicate the possible existence of a ferromagnetic liquid state, although definitive experimental evidence is lacking. Should such a state exist, demagnetization effects would…
Magnetic flux noise is a dominant source of dephasing and energy relaxation in superconducting qubits. The noise power spectral density varies with frequency as $1/f^\alpha$ with $\alpha \sim 1$ and spans 13 orders of magnitude. Recent work…
For nearly a decade, it has been a mystery why the small average number of photons absorbed per atom from an ultrashort laser pulse is able to induce a strong magnetization within a few hundred femtoseconds. Here we resolve this mystery by…
We investigate the modification in the optical properties of laser-excited bulk cobalt and nickel using the time-dependent density functional theory at a finite electron temperature. As a result of the first-principles simulation, a complex…
We use time-resolved x-ray resonant magnetic scattering (tr-XRMS) at the Co M$_{2,3}$- and Tb O$_1$-edges to study ultrafast demagnetization in an amorphous Co$_{88}$Tb$_{12}$ alloy with stripe domains. Combining the femtosecond temporal…
We compare femtosecond pump-probe experiments in Ni and micromagnetic modelling based on the Landau-Lifshitz-Bloch equation coupled to a two-temperature model, revealing a predominant thermal ultrafast demagnetization mechanism. We show…
The interface-induced magnetization damping of thin ferromagnetic films in contact with normal-metal layers is calculated from first principles for clean and disordered Fe/Au and Co/Cu interfaces. Interference effects arising from coherent…
Topological insulator (TI) thin films differ from the more commonly studied semi-infinite bulk TIs in that the former possesses both top and bottom surfaces where the surface states localized at different surfaces can couple to one another…
The ability to controllably manipulate the laser-induced ultrafast magnetic dynamics is a prerequisite for future high speed spintronic devices. The optimization of devices requires the controllability of the ultrafast demagnetization time,…
Engineering and controlling heat and spin transport on the femtosecond time-scale in spintronic devices opens up new ways to manipulate magnetization with unprecedented speed. Yet the underlying reversal mechanisms remain poorly understood…
We develop a theory of the magnetization dynamics triggered by ultrafast optical excitation of ferromagnetic semiconductors. We describe the effects of the strong carrier spin relaxation on the nonlinear optical response by using the…