相关论文: Femtosecond Control of the Magnetization in Ferrom…
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…
Using density matrix equations of motion, we predict a femtosecond collective spin tilt triggered by nonlinear, near--ultraviolet ($\sim$3eV), coherent photoexcitation of (Ga,Mn)As ferromagnetic semiconductors with linearly polarized light.…
Femtosecond (fs) coherent control of collective order parameters is important for non--equilibrium phase dynamics in correlated materials. Here we propose a possible scheme for fs control of a ferromagnetic order parameter based on…
Irradiating solids with ultrashort laser pulses is known to initiate femtosecond timescale magnetization dynamics. However, sub-femtosecond spin dynamics have not yet been observed or predicted. Here, we explore ultrafast light-driven spin…
A central prospect of antiferromagnetic spintronics is to exploit magnetic properties that are unavailable with ferromagnets. However, this poses the challenge of accessing such properties for readout and control. To this end, light-induced…
The nonlinearity of magnetization precession and spin waves is a cornerstone of contemporary magnonics. We investigate nonlinear magnetization dynamics in a thin epitaxial iron film driven by femtosecond laser pulses in regimes of…
The light-induced femtosecond dynamics of the sublattice magnetizations in the antiferromagnetically ordered phase of the semiconductor $\alpha$-MnTe is investigated theoretically as function of an external driving field. The…
Ultrafast laser pulses provide unique tools to manipulate magnetization dynamics at femtosecond timescales, where the interaction of the electric field -- such as excitation of spin carriers to non-equilibrium states, generation of…
By using intense coherent electromagnetic radiation, it may be possible to manipulate the properties of quantum materials very quickly, or even induce new and potentially useful phases that are absent in equilibrium. For instance, ultrafast…
The impulsive generation of two-magnon modes in antiferromagnets by femtosecond optical pulses, so-called femto-nanomagnons, leads to coherent longitudinal oscillations of the antiferromagnetic order parameter that cannot be described by a…
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…
Employing electron spin instead of charge to develop spintronic devices holds the merits of low-power consumption in information technologies. Meanwhile, the demand for increasing speed in spintronics beyond current CMOS technology has…
We demonstrate optical control of magnons using femtosecond laser pulses by performing ab-initio real-time time-dependent density functional theory (TDDFT) simulations. We predict that the spin-wave dynamics in Fe$_{50}$Ni$_{50}$ can be…
We theoretically consider magnetization dynamics in a ferromagnetic slab induced by the magnetic field of a strong femtosecond laser pulse. The longitudinal geometry, in which the initial magnetization lies in both the plane of incidence…
Using density matrix equations of motion and a tight-binding band calculation, we predict all-optical switching between four metastable magnetic states of (III,Mn)As ferromagnets. This switching is initiated non-thermally within 100fs,…
Optical control of magnetization is often symmetry-forbidden because electric fields and magnetization transform differently under inversion and time-reversal. However, through even-order nonlinear response, optical excitation can generate…
Laser-induced femtosecond demagnetization, femtomagnetism, offers a potential route to develop faster magnetic storage devices. It is generally believed that the traditional spin-wave theory, which is developed for thermally driven slow…
We analyze theoretically the novel pathway of ultrafast spin dynamics for ferromagnets with high enough single-ion anisotropy (non-Heisenberg ferromagnets). This longitudinal spin dynamics includes the coupled oscillations of the modulus of…
The magnetization of a non-magnetic semiconductor by femtosecond light pulses is crucial to achieve an all-optical control of the spin dynamics in materials and to develop faster memory devices. However, the conditions for its detection are…
A theoretical calculation is performed for the ultrafast spin dynamics in nickel using an exact diagonalization method. The present theory mainly focuses on a situation where the intrinsic charge and spin dynamics is probed by the nonlinear…