相关论文: Driving Force of Ultrafast Magnetization Dynamics
This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time this milestone work by Bigot and coworkers gave insight in a very direct way into the time scales of microscopic interactions that…
The dynamics of magnetic moments consist of a precession around the magnetic field direction and a relaxation towards the field to minimize the energy. While the magnetic moment and the angular momentum are conventionally assumed to be…
Terahertz (THz) lasers provide a new research perspective for spin electronics applications due to their sub-picosecond time resolution and non-thermal ultrafast demagnetization, but the interaction between spin, charge and lattice dynamics…
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…
Terahertz spin waves could be generated on-demand via all-optical manipulation of magnetization by femtosecond laser pulse. Here, we present an energy balance model, which explains the energy transfer rates from laser pulse to electron bath…
We present a theory for the coherent magnetization dynamics induced by a focused ultrafast laser beam in magnetic films, taking into account nonthermal (inverse Faraday effect) and thermal (heating) actuation. The dynamic conversion between…
We demonstrate that moving edge dislocations can induce the reversal of magnetization in a ferromagnetic film due to the Barnett effect. The dynamics of magnetization is studied numerically within a discretized Landau-Lifshitz equation on a…
Ultrafast demagnetization of magnetic layers pumped by a femtosecond laser pulse is accompanied by a nonthermal spin-polarized current of hot electrons. These spin currents are studied here theoretically in a spin valve with noncollinear…
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…
Following the demonstration of laser-induced ultrafast demagnetization in ferromagnetic nickel, several theoretical and phenomenological propositions have sought to uncover its underlying physics. In this work we revisit the three…
Optical control of magnetism, of interest for high-speed data processing and storage, has only been demonstrated with near-infrared excitation to date. However, in absorbing materials, such high photon energies can lead to significant…
The exchange interaction among electrons is one of the most fundamental quantum mechanical interactions in nature and underlies any magnetic phenomena from ferromagnetic ordering to magnetic storage. The current technology is built upon a…
Interest in femtosecond demagnetization experiments was sparked by Bigot's discovery in 1995. These experiments unveil the elementary mechanisms coupling the electrons' temperature to their spin order. Even though first quantitative models…
Subpicosecond laser excitation of ferromagnetic metals induces strongly nonequilibrium dynamics involving scattering and transport of electrons, phonons, and magnons. Widely used theoretical approaches, such as the three-temperature model…
Laser-induced terahertz spin transport (TST) and ultrafast demagnetization (UDM) are central but so far disconnected phenomena in femtomagnetism and terahertz spintronics. Here, we use broadband terahertz emission spectroscopy to reliably…
Ultrafast demagnetization induced by femtosecond laser pulses in thin metallic layers is caused by the outflow of spin-polarized hot electron currents describable by the superdiffusive transport model. These laser-generated spin currents…
An internal anisotropy pulse field is launched by an 8.3 ps short laser excitation, which triggers precessional magnetization dynamics of a polycrystalline NiFe/FeMn exchange bias system on the picosecond timescale. Due to the excitation…
Ultrafast magnetization dynamics in metallic heterostructures consists of a combination of local demagnetization in the ferromagnetic constituent and spin-dependent transport contributions within and in between the constituents. Separation…
Magnetization manipulation is becoming an indispensable tool for both basic and applied research. Theory predicts two types of ultrafast demagnetization dynamics classified as type I and type II. In type II materials, a second slower…
The Barnett effect, discovered more than a century ago, describes how an inertial body with otherwise zero net magnetic moment acquires spontaneous magnetization when mechanically spinning. Breakthrough experiments have recently shown that…