Institut des
NanoSciences de Paris
insp
Accueil > Evénements > Séminaires > Archives 2015 > A Time-Domain View (...)
insp
4.jpg

Séminaire Magnétisme et Physique du spin de l’INSP

A Time-Domain View on Ultrafast Magnetoelasticity - Ra’anan I. Tobey - Mercredi 28 octobre 2015 à 11 h

INSP - 4 place Jussieu - 75252 PARIS Cedex 05 - Barre 22-32 - 4e étage, salle 407

Ra’anan I. Tobey - Zernike Institute for Advanced Materials - University of Groningen, NL

Abstract

Control of material properties is one of the driving forces in ultrafast optical sciences. The notion that light can influence intrinsic material parameters is founded on a wide range of experiments demonstrating opto-magnetic control, light induced superconductivity, and the photo induced insulator to metal transition in a wide range of materials. A recent addition to the tool chest of control methodologies is the excitation of acoustic waves, and their affect on intrinsic materials properties ; particularly the material magnetization via magnetostrictive effects. In this talk I will describe our recent results[1] where we optically generate in-plane magneto elastic waves in the test material nickel. Using a combination of the transient grating and Faraday techniques, we probe the magnetic components of the intrinsically acoustic excitations generated in the TG geometry. The dispersion characteristics of our excitations can be uniquely identified as arising from in-plane Rayleigh and Longitudinal acoustic excitations. At particular values of applied external magnetic field, the acoustic excitation couples to a k-vector tunable ferromagnetic resonance in the film. Figure : Magnetic precession frequency as a function of in-plane applied magnetic field. The oscillation amplitude is maximized when the acoustic frequency (white horizontal line) matches the FMR resonance (red line) and demonstrates the resonant coupling of the elastic wave to the magnetic precession.

[1] J. Janusonis et.al. APL 106, 181601 (2015).