Selective surface/interface characterization of thin garnet films by magnetization-induced second-harmonic generation

Hansteen, Fredrik; Hunderi, O.; Johansen, T. H.; Kirilyuk, Andrei; Rasing, T.H.M.

doi:10.1103/physrevb.70.094408

Cited by 19 publications

(13 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While bulk garnet crystals have cubic symmetry and possess a center of inversion, epitaxially grown thin garnet films seem to lack this center of symmetry, as has been demonstrated by the existence of a linear magnetoelectric effect 49 and by strong optical second-harmonic generation. 50,51 The garnet films were studied in transmission using an all-optical pump and probe technique. Regeneratively amplified 100 fs pulses of wavelength = 805 nm emitted from a Ti:Sapphire laser system at a repetition rate of 1 kHz were split into two parts using a beam splitter.…”

Section: Methodsmentioning

confidence: 99%

Nonthermal ultrafast optical control of the magnetization in garnet films

et al. 2006

Self Cite

View full text Add to dashboard Cite

We demonstrate coherent optical control of the magnetization in ferrimagnetic garnet films on the femtosecond time scale through a combination of two different ultrafast and nonthermal photomagnetic effects and by employing multiple pump pulses. Linearly polarized laser pulses are shown to create a long-lived modification of the magnetocrystalline anisotropy via optically induced electron transfer between nonequivalent ion sites while circularly polarized pulses additionally act as strong transient magnetic field pulses originating from the nonabsorptive inverse Faraday effect. Due to the slow phonon-magnon interaction in these dielectrics, thermal effects of the laser excitation are clearly distinguished from the ultrafast nonthermal effects and can be seen only on the time scale of nanoseconds for sample temperatures near the Curie point. The reported effects open exciting possibilities for ultrafast manipulation of spins by light, and provide insight into the physics of magnetism on ultrafast time scales.

show abstract

Section: Methodsmentioning

confidence: 99%

Nonthermal ultrafast optical control of the magnetization in garnet films

et al. 2006

Self Cite

View full text Add to dashboard Cite

show abstract

“…The sample was grown on a (001) oriented gadolinium gallium garnet substrate with trace amounts of Pb impurities resulting from the growth process. This sample has a magnetisation of M s = 300 kA m −1 [37] and a weak in-plane fourfold anisotropy field 4 kA m −1 which results, in the absence of magnetic fields, in four equilibrium orientations of the magnetisation that are orthogonal to each other in the plane of the film.…”

Section: Methodsmentioning

confidence: 99%

Dynamic self-organisation and pattern formation by magnon-polarons

Gidding¹,

Janssen²,

S.³

et al. 2022

Preprint

View full text Add to dashboard Cite

Nonlinear dynamics can give rise, via the processes of self-organisation and pattern formation, to the spontaneous manifestation of order in open and complex systems far from equilibrium. Self-organising systems, transforming the inflow of energy into information, are ubiquitously found in current topical areas of science ranging from brainwave entrainment and neuromorphic computing to energy-efficient data storage technologies. In the latter, magnetic materials play a pivotal role combining very fast switching with permanent retention of information. However, it has been shown that, at very short time scales, magnetisation dynamics become chaotic due to internal instabilities, resulting in incoherent spin-wave excitations that ultimately destroy magnetic ordering. Here, contrary to all expectations, we show that such chaos gives rise to a periodic pattern of reversed magnetic domains, with a feature size far smaller than the spatial extent of the excitation. We explain this pattern as a result of phase-synchronisation of magnon-polaron waves, driven by strong coupling of magnetic and elastic modes. Our results reveal not only the peculiar formation and evolution of magnon-polarons at short time-scales, but also present a novel mechanism of magnetization reversal driven by coherent packets of short-wavelength quasiparticles.Finding methods that enable fast, efficient and long-lasting reversal of magnetisation direction represents a major topic of research in condensed matter physics with obvious technological applications [1]. The most theoreticallystraightforward but also practical approach for switching magnetisation 1

show abstract

“…The quantitative values of the elements of the coupling tensor Γ αβγ have been chosen based on the values for the susceptibility χ αβγ experimentally determined and reported in [58]. Although, the exact numerical values with corresponding units could not be deduced from [58], we adopted the relations between the different tensor components mentioned in this article. In the present model the tensor components Σ α always occur in product with the saturation magnetization M s .…”

Section: Model Parametersmentioning

confidence: 99%

Nonlinear magneto-optical response to light carrying orbital angular momentum

Bose¹,

Berakdar²

2014

J. Opt.

View full text Add to dashboard Cite

We predict a non-thermal magneto-optical effect for magnetic insulators subject to intense light carrying orbital angular momentum (OAM). Using a classical approach to second harmonic generation in non-linear media with specific symmetry properties we predict a significant nonlinear contribution to the local magnetic field triggered by light with OAM. The resulting magnetic field originates from the displacement of electrons driven by the electrical field (with amplitude E 0 ) of the spatially inhomogeneous optical pulse, modeled here as a Laguerre-Gaussian beam carrying OAM. In particular, the symmetry properties of the irradiated magnet allow for magnetic field responses which are second-order (∼ E 2 0 ) and fourth-order (∼ E 4 0 ) in electric-field strength and have opposite signs. For sufficiently high laser intensities, terms ∼ E 4 0 dominate and generate magnetic field strengths which can be as large as several Tesla. Moreover, changing the OAM of the laser beam is shown to determine the direction of the total light-induced magnetic field, which is further utilized to study theoretically the non-thermal magnetization dynamics.

show abstract

Selective surface/interface characterization of thin garnet films by magnetization-induced second-harmonic generation

Cited by 19 publications

References 19 publications

Nonthermal ultrafast optical control of the magnetization in garnet films

Nonthermal ultrafast optical control of the magnetization in garnet films

Dynamic self-organisation and pattern formation by magnon-polarons

Nonlinear magneto-optical response to light carrying orbital angular momentum

Contact Info

Product

Resources

About