相关论文: Ab initio dynamical exchange interactions in frust…

Since the beginning of femtomagnetism, it has been hotly debated how an ultrafast laser pulse can demagnetize a sample and switch its spins within a few hundred femtoseconds, but no consensus has been reached. In this paper, we propose that…

Ultrashort optical pulses are a cornerstone for manipulating electronic and magnetic states in materials on a femtosecond timescale. Conventional models assume that optical excitation primarily modifies the occupation of the electron energy…

Interest in all-optical spin switching (AOS) is growing rapidly. The recent discovery of AOS in Mn$_2$RuGa provides a much needed clean case of crystalline ferrimagnets for theoretical simulations. Here, we attempt to simulate it using the…

Electronic excitations in a ferromagnet can trigger ultrafast spin dynamics with potential applications in a speed increase in magnetic recording. The project investigates ultrafast magnetization dynamics, which is driven in metallic layers…

Induced by an ultra-short laser pulse, the electronic structure of a material undergoes strong modifications leading to a fast demagnetization in magnetic materials. Induced spin-flip transitions are one of the reasons for demagnetization,…

Exchange interactions determine the correlations between microscopic spins in magnetic materials. Probing the dynamics of these spin correlations on ultrashort length and time scales is, however rather challenging, since it requires…

When a laser pulse excites a ferromagnet, its spin undergoes a dramatic change. The initial demagnetization process is very fast. Experimentally, it is found that the demagnetization time is related to the spin moment in the sample. In this…

We report on {\it ab initio} time-dependent spin dynamics simulations for a two-center magnetic molecular complex based on time-dependent non-collinear spin density functional theory. In particular, we discuss how the dynamical behavior of…

The magnetization dynamics of a synthetic antiferromagnet subject to a short magnetic field pulse, has been studied by using a combination of first-principles and atomistic spin dynamics simulations. We observe switching phenomena on the…

We bridge an essential knowledge gap on the understanding of all-optical ultrafast switching in ferrimagnets; namely, the connection between atomistic spin dynamics methods and macroscopic phenomenological models. All-optical switching of…

Laser radiation incident on a ferromagnetic sample produces excited electrons and currents whose spin polarization must not be aligned with the magnetization -- an effect due to spin-orbit coupling that is ubiquitous in spin- and…

We investigate the interaction of femtosecond laser pulses with spins including relativistic corrections. The time-ordered magneto-optical signals corresponding to a pump-probe configuration are calculated in the case of one electron…

Time-dependent density functional theory is implemented in an all electron solid-state code for the case of fully non-collinear spins. We use this to study laser induced demagnetization in Fe, Co and Ni. It is shown that this…

We derive the Heisenberg representation of the ultrafast inverse Faraday effect that provides the time evolution of magnetic vectors of a magnetic system during its interaction with a laser pulse. We obtain a time-dependent effective…

The dynamics of single laser-driven electrons and many particle systems with spin are investigated on the basis of a classical theory. We demonstrate that the spin forces can alter the electron dynamics in an ultra-relativistic laser field…

We theoretically study the dynamic time evolution following laser pulse pumping in an antiferromagnetic insulator Cr$_{2}$O$_{3}$. From the photoexcited high-spin quartet states to the long-lived low-spin doublet states, the ultrafast…

In the exchange approximation, an exact solution is obtained for the sublattice magnetizations evolution in a two-sublattice ferrimagnet. Nonlinear regimes of spin dynamics are found that include both the longitudinal and precessional…

It is found that subtle changes in the external magnetic field and temperature result in dramatic changes in the ultrafast response of spins to a femtosecond laser excitation in a ferrimagnetic Gd/FeCo multilayer. A total of six distinct…

Using an ultrashort laser pulse we explore {\it ab-initio} the spin dynamics of Gd$_x$(FeCo)$_{1-x}$ at femtosecond time scales. Optical excitations are found to drive charge from Fe majority $d$-states to the unoccupied Gd $f$-minority…

Manipulating spin in antiferromagnetic (AFM) materials has great potential in AFM opto-spintronics. Laser pulses can induce a transient ferromagnetic (FM) state in AFM metallic systems, but have never been proven in two-dimensional (2D) AFM…