Laser Excitation of Lattice-Driven Anharmonic Magnetization Dynamics in DielectricFeBO3

Abstract

Femtosecond laser pulses trigger in dielectric FeBO3 coherent oscillations of the magnetic anisotropy followed by spins. The oscillations are driven by optically excited lattice vibrations strongly coupled to the magnetic system. Unlike the spin resonances, this mode is characterized by a very small damping ratio and can be easily pushed into an anharmonic regime.

Parametric frequency mixing in a magnetoelastically driven linear ferromagnetic-resonance oscillator

“…In recent years, magnetoelastic interactions have seen a resurgence of interest, and linear coupling between these degrees of freedom have been demonstrated [16][17][18][19][20][21]. To our knowledge, only a single report has discussed the potential for nonlinearities in the magnetoelastic interactions [22].…”

“…In recent years, magnetoelastic interactions have seen a resurgence of interest, and linear coupling between these degrees of freedom have been demonstrated [16][17][18][19][20][21]. To our knowledge, only a single report has discussed the potential for nonlinearities in the magnetoelastic interactions [22].In this report we present experimental evidence for the nonlinear (in the sense of frequency mixing) interaction between multiple coherent elastic deformations and the magnetization precession in a thin ferromagnetic film. To explain our results we perform analytical calculations of the Landau-Lifshitz-Gilbert equation, subject to the periodic excitation of a large amplitude, coherent elastic wave and show that the resulting dynamics can be described by an extended Mathieu equation for a nonlinear parametric oscillator.…”

Resonant driving of magnetization precession in a ferromagnetic layer by coherent monochromatic phonons

“…The typical frequencies f M of the magnetic resonances [e.g., the ferromagnetic resonance (FMR) in ferromagnetic and ferrimagnetic materials] are in the GHz and sub-THz frequency ranges. The traditional methods to scan magnetic excitations at these frequencies use microwaves, but due to the requirement of massive microwave resonators providing long wavelength radiation, they cannot provide high-speed control of magnetization locally on the nanoscale.Among various emerging techniques in nanomagnetism, the application of stress to magnetostrictive ferromagnetic layers has been shown to be an effective, low-power method for controlling magnetization: Applying in-plane stress in stationary experiments enables irreversible switching of the magnetization vector [10]; the injection of picosecond strain pulses induces free precession of the magnetization [11]; excitation of quantized elastic waves in a membrane enables driving of the magnetization at GHz phonon frequencies [12]; and surface acoustic waves can be used to control the magnetic dynamics in ferromagnetic nanostructures [13][14][15]. In the present Rapid Communication, we examine the interaction of a high-frequency (10−40 GHz) magnetic resonance in a magnetostrictive ferromagnetic film with an elastic harmonic excitation in the form of a localized phonon mode, and demonstrate how this interaction becomes significantly stronger at resonance conditions.…”

Strain and Thermally Induced Magnetic Dynamics and Spin Current in Magnetic Insulators Subject to Transient Optical Grating

“…Fueled by potential applications in spintronics and sensorics thermal and magnetoelastic driven magnetic dynamics is attacking a great deal of research (Davis et al, 2010;Scherbakov et al, 2010;Roy et al, 2011;Uchida et al, 2011a;Weiler et al, 2011;Azovtsev and Pertsev, 2016). Elastic excitations might be triggered in a variety of ways, for instance via acoustic transducers (Davis et al, 2010;Uchida et al, 2011b;Weiler et al, 2011Weiler et al, , 2012Thevenard et al, 2013) or by optical methods (Scherbakov et al, 2010;Kim et al, 2012;Jäger et al, 2013;Kovalenko et al, 2013;Afanasiev et al, 2014). Optical methods mainly generate elastic excitations via laser heating and thermoelastic effects.…”

“…Optical methods mainly generate elastic excitations via laser heating and thermoelastic effects. As compared to transducers, laser pulses achieve larger amplitude thermoelastic deformations (Saito et al, 2003;Scherbakov et al, 2010;Kim et al, 2012;Jäger et al, 2013;Kovalenko et al, 2013;Afanasiev et al, 2014). A further interesting method to induce magnetoelastic excitations via electric fields is to use multiferroics materials, particularly heterostructures of coupled piezoelectric or ferroelectric and ferromagnetic layers (Vaz, 2012;Cherepov et al, 2014;Jia et al, 2014Jia et al, , 2016Gilbert et al, 2016).…”