Linear Contribution to Spatial Dispersion in the Spin-Wave Spectrum of Ferromagnets

Melcher, R. L.

doi:10.1103/physrevlett.30.125

Cited by 63 publications

(36 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(E 0 stands for a gap energy.) This shifted quadratic magnon dispersion relation has been known theoretically for decades, and was microscopically attributed to the antisymmetric Dzyaloshinskii-Moriya (DM) interaction originating from the relativistic spin-orbit coupling 9,10 .…”

Section: Introductionmentioning

confidence: 85%

Magnon dispersion shift in the induced ferromagnetic phase of noncentrosymmetric MnSi

et al. 2016

View full text Add to dashboard Cite

Small angle neutron inelastic scattering measurement has been performed to study the magnon dispersion relation in the field-induced-ferromagnetic phase of the noncentrosymmetric binary compound MnSi. For the magnons propagating parallel or anti-parallel to the external magnetic field, we experimentally confirmed that the dispersion relation is asymmetrically shifted along the magnetic field direction. This magnon dispersion shift is attributed to the relativistic Dzyaloshinskii-Moriya interaction, which is finite in noncentrosymmetric magnets, such as MnSi. The shift direction is found to be switchable by reversing the external magnetic field direction.

show abstract

Section: Introductionmentioning

confidence: 85%

Magnon dispersion shift in the induced ferromagnetic phase of noncentrosymmetric MnSi

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Particularly at high field as well as for small 2, when the calculated vortex radius goes to zero, one might suspect a radial instability, leading to a spontaneous collapse of the vortices. To check the radial stability we use a scale transformation In ordinary ferromagnets with e, = 0 solutions with a well defined radius are impossible because any radial transformation (15) would leave the total energy invariant according to (16). A solution could theoretically have the "soft" character which Belavin and Polyakov [34] found in materials without any magnetic field or anisotropy.…”

Section: Radial Stability Of Solutionsmentioning

confidence: 99%

“…In contrast, modulated structures based on the Dzyaloshinsky interaction have a fixed rotation sense and rather long periods. They were shown to exist in cubic materials like MnSi, Fe,Co,-,Si, Co,Mn, _,Si [7 to 131, in the hexagonal antiferromagnet CsCuC1, [14], and in other magnetic crystals [6, 151. For the theoretical analysis of these spin structures see [13,16 to 211. The same kind of structures can also be induced by magnetic and electric fields and by external or internal stresses [6, 211. In magnetic superlattices consisting of MnSe and ZnTe layers [22] and also in epitaxial films of Cd,-,Mn,Se [23] tensile strains were recently shown to induce incommensurate helical spin structures belonging to this class of phenomena.…”

mentioning

confidence: 99%

The Properties of Isolated Magnetic Vortices

Bocdanov

Hubert

1994

Physica Status Solidi (b)

188

244

View full text Add to dashboard Cite

Isolated magnetic vortices are stabilized by an antisymmetric exchange interaction, the so-called Dzyaloshinsky interaction, which can be represented as an energy contribution linear in the first spatial derivatives of the magnetization vector. In contrast, vortex lines are demonstrated to be unstable in the bulk of regular uniaxial ferromagnets. They collapse spontaneously under the influence of anisotropy or an applied magnetic field. In reduced units the differential equation for isolated vortices contains two parameters: the reduced magnetic field h along the crystal axis and the material parameter 2 which describes the relative contribution of the Dzyaloshinsky interaction term. Isolated vortices turn out to be always metastable for large fields, independent of R as long as this parameter is positive. At low or negative fields they become unstable by two different mechanisms depending on the %value, but altogether these micromagnetic structures turn out to be stable in a remarkably wide range of parameters. At the end possible applications are considered.Isolierte mikromagnetische Wirbel werden durch eine antisymmetrische Austauschkopplung, eine sogenannte Dzyaloshinsky-Wechselwirkung, stabilisiert. Eine derartige Kopplung laat sich mikromagnetisch als Energiebeitrag darstellen, der linear in den Ortsableitungen des Magnetisierungsfeldes ist. Im Gegensatz dazu wird gezeigt, dai3 Wirbellinien im Innern gewohnlicher einachsiger Ferromagnete instabil sind, da sie spontan unter der Wirkung der magnetischen Anisotropie oder eines angelegten Feldes kollabieren. Die sich ergebende Differentialgleichung hangt in reduzierter Darstellung von zwei Parametern ab: dem reduzierten Feld h entlang der leichten Achse des Kristalls und dem Materialparameter 2, der die relative Starke des Koefizienten der Dzyaloshinsky-Wechselwirkung miBt. Isolierte Magnetisierungswirbel erweisen sich als metastabil in beliebig hohen Feldern, unabhangig von 2, solange dieser Parameter positiv ist. In kleinen oder negativen Feldern werden sie je nach der GroBe von 2 auf Grund zweier verschiedener Mechanismen instabil. Insgesamt weisen diese mikromagnetischen Gebilde aber einen bemerkenswert weiten Stabilitatsbereich auf. Im SchluDkapitel werden Uberlegungen zu moglichen Anwendungen angestellt.

show abstract

“…Non-reciprocal magnon transport is usually associated with an asymmetric dispersion ε(q) = ε(−q) for the spin waves. This arises, in particular, in the field-polarized state of chiral magnets [14,15]. As a consequence, the group velocity ∂ q ε(q) remains finite in the limit of small wavevector, q → 0, which is routinely used to determine the size of the Dzyaloshinskii-Moriya interaction [16][17][18][19][20].…”

mentioning

confidence: 99%

Polarized inelastic neutron scattering of nonreciprocal spin waves in MnSi

et al. 2019

View full text Add to dashboard Cite

We report spin-polarized inelastic neutron scattering of the dynamical structure factor of the conical magnetic helix in the cubic chiral magnet MnSi. We find that the spectral weight of spinflip scattering processes is concentrated on single branches for wavevector transfer parallel to the helix axis as inferred from well-defined peaks in the neutron spectra. In contrast, for wavevector transfers perpendicular to the helix the spectral weight is distributed among different branches of the magnon band structure as reflected in broader features of the spectra. Taking into account the effects of instrumental resolution, our experimental results are in excellent quantitative agreement with parameter-free theoretical predictions. Whereas the dispersion of the spin waves in MnSi appears to be approximately reciprocal at low energies and small applied fields, the associated spinresolved spectral weight displays a pronounced non-reciprocity that implies a distinct non-reciprocal response in the limit of vanishing uniform magnetization at zero magnetic field. This is a pre-print of our paper [1] at http://dx.

show abstract

Linear Contribution to Spatial Dispersion in the Spin-Wave Spectrum of Ferromagnets

Cited by 63 publications

References 7 publications

Magnon dispersion shift in the induced ferromagnetic phase of noncentrosymmetric MnSi

Magnon dispersion shift in the induced ferromagnetic phase of noncentrosymmetric MnSi

The Properties of Isolated Magnetic Vortices

Polarized inelastic neutron scattering of nonreciprocal spin waves in MnSi

Contact Info

Product

Resources

About