相关论文: Laser-induced forces on atoms during ultrafast dem…
In past decades, ultrafast spin dynamics in magnetic systems have been associated with heat deposition from high energy laser pulses, limiting the selective access to spin order. Here we use a long wavelength terahertz pump optical probe…
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…
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…
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…
We show the possible excitation of a phonon laser instability in an ultra-cold atomic gas confined in a magneto-optical trap. Such an effect results from a negative Landau damping of the collective density perturbations in the gas, leading…
The ultrafast non-thermal control of magnetization has recently become feasible in canted antiferromagnets through photomagnetic instantaneous pulses [A.V. Kimel {\it et al.}, Nature {\bf 435}, 655 (2005)]. In this experiment circularly…
Recent advances in ultrashort laser pulse techniques have opened up a wide variety of applications in both fundamental physics and industrial fields. In this work, $ab$ $initio$ molecular dynamics simulations based on time-dependent density…
Magnetocaloric (MC) materials present an avenue for chemical-free, solid state refrigeration through cooling via adiabatic demagnetization. We have used inelastic neutron scattering to measure the lattice dynamics in the MC material…
The ultrafast dynamics of magnetic order in a ferromagnet are governed by the interplay between electronic, magnetic and lattice degrees of freedom. In order to obtain a microscopic understanding of ultrafast demagnetization, information on…
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…
Excitation of a metallic ferromagnet such as Ni with an intensive femtosecond laser pulse causes an ultrafast demagnetization within approximately 300 fs. It was proposed that the ultrafast demagnetization measured in femtosecond…
Light-matter interaction at the nanoscale in magnetic alloys and heterostructures is a topic of intense research in view of potential applications in high-density magnetic recording. While the element-specific dynamics of electron spins is…
We propose a kinetic model of transient nonequilibrium phenomena in metals exposed to ultrashort laser pulses when heated electrons affect the lattice through direct electron-phonon interaction. This model describes the destruction of a…
Ultrafast electron delocalization induced by a fs laser pulse is a well-known process and is the initial step for important applications such as fragmentation of molecules or laser ablation in solids. It is well understood that an intense…
We present a numerical study of the behaviour of two magnetic dipolar atoms trapped in a harmonic potential and exhibiting the standard Einstein-de Haas effect while subject to a time dependent homogeneous magnetic field. Using a simplified…
The possibilities to induce magnetism in the non-magnetic bulk alpha-FeSi2 by means of lattice distortions or intercalation with metal or non-metal ions of light elements is investigated theoretically by combined ab initio and model…
Here we carry out a first-principles time-dependent calculation to investigate how fast electrons actually move under laser excitation and how large the electron transport affects demagnetization on the shortest time scale. To take into…
The dynamics of ultrafast demagnetisation in 3$d$ magnets is complicated by the presence of both spin ${\v S}$ and orbital ${\v L}$ angular momentum, with the microscopic mechanism by which the magnetic moment is redistributed to the…
Since the discovery of ultrafast demagnetization in Ni thin films in 1996, laser-induced ultrafast spin dynamics have become a prominent research topic in the field of magnetism and spintronics. This development offers new possibilities for…
We theoretically investigate spin-dependent carrier dynamics due to the electron-phonon interaction after ultrafast optical excitation in ferromagnetic metals. We calculate the electron-phonon matrix elements including the spin-orbit…