Femtosecond Laser Excitation of Spin Resonances in Amorphous Ferrimagnetic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>Gd</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Co</mml:mi><mml:mi>x</mml:mi></mml:msub></mml:math>Alloys

Mekonnen, A.; Cormier, M.; Kimel, A.V.; Kirilyuk, Andrei; Hrabec, Aleš; Ranno, Laurent; Rasing, T.H.M.

doi:10.1103/physrevlett.107.117202

Cited by 41 publications

(33 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in agreement with our interpretation based on strain-induced changes of magnetic anisotropy via the inverse magnetostriction effect. Indeed, in the case of thermally induced spin precession a dependence of the frequency on E pump is usually observed [56,57]. On the other hand, the behavior of f acous as a function of E pump is also in agreement with the prediction that the frequency of acoustically-induced modulation of the MO effects is mainly defined by the speed of sound.…”

Section: Results and Disccussionsupporting

confidence: 83%

Picosecond acoustic-excitation-driven ultrafast magnetization dynamics in dielectric Bi-substituted yttrium iron garnet

et al. 2018

View full text Add to dashboard Cite

Using femtosecond optical pulses, we have investigated the ultrafast magnetization dynamics induced in a dielectric film of bismuth-substituted yttrium iron garnet (Bi-YIG) buried below a thick Cu/Pt metallic bilayer. We show that exciting the sample from Pt surface launches an acoustic strain pulse propagating into the garnet film. We discovered that this strain pulse induces a coherent magnetization precession in the Bi-YIG at the frequency of the ferromagnetic resonance. The observed phenomena can be explain by strain-induced changes of magnetocristalline anisotropy via the inverse magnetostriction effect. These findings open new perspectives toward the control of the magnetization in magnetic garnets embedded in complex heterostructure devices.

show abstract

Section: Results and Disccussionsupporting

confidence: 83%

Picosecond acoustic-excitation-driven ultrafast magnetization dynamics in dielectric Bi-substituted yttrium iron garnet

et al. 2018

View full text Add to dashboard Cite

show abstract

“…11,[31][32][33][34][35][36] Recently we showed that a minimum amount of laser energy input of the order of the energy gap between the two ferrimagnetic modes, i.e.h∆ω ∼hω ex ∼ J RT (M FeCo (T 0 ) − M Gd (T 0 )), is required for the formation of the TFLS, 11 where ω ex is the frequency of the so-called antiferromagnetic coherent exchange mode. The disordered nature of the GdFeCo spin lattice leads an effect that the most efficient energy transfer (the smallest energy gap) does not correspond exactly to the coherent mode with k = 0 but to non-zero k value, related to the characteristic length of the Gd spins cluster size.…”

Section: B Formation Of the Transient Ferromagnetic Like Statementioning

confidence: 99%

Controlling the polarity of the transient ferromagneticlike state in ferrimagnets

et al. 2014

View full text Add to dashboard Cite

It was recently observed that the two antiferromagnetically coupled sublattices of a rare earth-transition metal ferrimagnet can temporarily align ferromagnetically during femtosecond laser heating, but always with the transition metal aligning in the rare earth direction. This behavior has been attributed to the slower magnetization dynamics of the rare earth sublattice. The aim of this work was to assess how the difference in the speed of the transition metal and rare earth dynamics affects the formation of the transient ferromagnetic-like state and consequently controls its formation. Our investigation was performed using extensive atomistic spin simulations and analytic micromagnetic theory of ferrimagnets, with analysis of a large area of parameter space such as initial temperature, Gd concentration and laser fluence. Surprisingly, we found that at high temperatures, close to the Curie point, the rare earth dynamics become faster than those of the transition metal. Subsequently we show that the transient state can be formed with the opposite polarity, where the rare earth aligns in the transition metal direction. Our findings shed light on the complex behavior of this class of ferrimagnetic materials and highlight an important feature which must be considered, or even exploited, if these materials are to be used in ultrafast magnetic devices.

show abstract

“…While in some cases good agreement between these distinct techniques have been reported 12,13 , there is often significant disagreement between the methods 14,15 . 4 When the time resolved pump-probe method is implemented using the magneto optical Kerr effect (TRMOKE), a clear advantage over the FMR method is gained in the ability to operate at very high fields and frequencies 16,17 . On the other hand, the FMR method allows operation over a wider range of geometrical configurations.…”

Section: Introductionmentioning

confidence: 99%

Determination of intrinsic damping of perpendicularly magnetized ultrathin films from time-resolved precessional magnetization measurements

et al. 2015

View full text Add to dashboard Cite

Abstract:Magnetization dynamics are strongly influenced by damping, namely the loss of spin angular momentum from the magnetic system to the lattice. An "effective" damping constant αeff is often determined experimentally from the spectral linewidth of the free induction decay of the magnetization after the system is excited to its non-equilibrium state. Such an αeff, however, reflects both intrinsic damping as well as inhomogeneous broadening that arises, for example, from spatial variations of the anisotropy field. In this paper we compare measurements of the magnetization dynamics in ultrathin non-epitaxial films having perpendicular magnetic anisotropy using two different techniques, timeresolved magneto optical Kerr effect (TRMOKE) and hybrid optical-electrical ferromagnetic resonance (OFMR). By using an external magnetic field that is applied at very small angles to the film plane in the TRMOKE studies, we develop an explicit closedform analytical expression for the TRMOKE spectral linewidth and show how this can be used to reliably extract the intrinsic Gilbert damping constant. The damping constant determined in this way is in excellent agreement with that determined from the OFMR method on the same samples. Our studies indicate that the asymptotic high-field approach that is often used in the TRMOKE method to distinguish the intrinsic damping from the 2 effective damping may result in significant error, because such high external magnetic fields are required to make this approach valid that they are out of reach. The error becomes larger the lower is the intrinsic damping constant, and thus may account for the anomalously high damping constants that are often reported in TRMOKE studies. In conventional ferromagnetic resonance (FMR) studies, inhomogeneous contributions can be readily distinguished from intrinsic damping contributions from the magnetic field dependence of the FMR linewidth. Using the analogous approach, we show how reliable values of the intrinsic damping can be extracted from TRMOKE in two distinct magnetic systems with significant perpendicular magnetic anisotropy: ultrathin CoFeB layers and Co/Ni/Co trilayers.3

show abstract

Femtosecond Laser Excitation of Spin Resonances in Amorphous FerrimagneticGd1−xCoxAlloys

Cited by 41 publications

References 26 publications

Picosecond acoustic-excitation-driven ultrafast magnetization dynamics in dielectric Bi-substituted yttrium iron garnet

Picosecond acoustic-excitation-driven ultrafast magnetization dynamics in dielectric Bi-substituted yttrium iron garnet

Controlling the polarity of the transient ferromagneticlike state in ferrimagnets

Determination of intrinsic damping of perpendicularly magnetized ultrathin films from time-resolved precessional magnetization measurements

Contact Info

Product

Resources

About