Magnetic domain-wall motion by propagating spin waves

Han, Dong‐Soo; Kim, Sang‐Koog; Lee, Jun-Young; Hermsdoerfer, S. J.; Schultheiß, Helmut; Leven, B.; Hillebrands, B.

doi:10.1063/1.3098409

Cited by 150 publications

(159 citation statements)

References 24 publications

Supporting

Mentioning

151

Contrasting

Order By: Relevance

“…In terms of DW propagation direction, the pure magnonic STT predicts [15] a DW moving against magnon propagation direction. However, a DW may also propagate along magnon flow direction [17][18][19]. This is very similar to electric-current-driven DW motion: A DW propagates along or against electron flow direction, depending on detailed spin-orbit interactions and DW types [20][21][22].…”

mentioning

confidence: 99%

Thermodynamic theory for thermal-gradient-driven domain-wall motion

Wang

2014

Phys. Rev. B

View full text Add to dashboard Cite

Spin waves (or magnons) interact with magnetic domain walls (DWs) in a complicated way that a DW can propagate either along or against magnon flow. However, thermally activated magnons always drive a DW to the hotter region of a nanowire of magnetic insulators under a temperature gradient. We theoretically illustrate why it is surely so by showing that DW entropy is always larger than that of a domain as long as material parameters do not depend on spin textures. Equivalently, the total free energy of the wire can be lowered when the DW moves to the hotter region. The larger DW entropy is related to the increase of magnon density of states at low energy originated from the gapless magnon bound states. Manipulation of a magnetic domain wall (DW) in a nanostructure has attracted much attention due to its application prospects in logical operations [1] and data storage [2]. Moving DWs in a controlled manner is an important issue in those applications. Magnetic fields via energy dissipation [3][4][5] and electric current via angular momentum transfer [6][7][8] are well-known control parameters for DW motion. To overcome the Joule heating [7] in current driven magnetization reversal, heat itself has recently been proposed [9] as an efficient control parameter for spin manipulation. A temperature gradient can generate spin current [10][11][12] due to electron and/or magnon flow. This thermoelectric phenomenon of spin current generation is called spin Seebeck effect that has been experimentally observed through the inverse spin Hall effect [10]. The spin Seebeck effect has also been suggested [13,14] as a control parameter for DW manipulation. As spin-1 carriers, magnons can mediate a spin transfer torque (STT) [15] on a magnetic texture like a DW in a similar way as the electrons do. It was predicted [13,14] that a thermal-magnon-driven DW can propagate along a wire at a high speed, and this prediction was confirmed in a recent experiment [16].There is little doubt that magnonic STT can drive a DW to move. In terms of DW propagation direction, the pure magnonic STT predicts [15] a DW moving against magnon propagation direction. However, a DW may also propagate along magnon flow direction [17][18][19]. This is very similar to electric-current-driven DW motion: A DW propagates along or against electron flow direction, depending on detailed spin-orbit interactions and DW types [20][21][22]. It is not clear whether magnon-driven "wrong" DW propagation direction shares a similar physics origin as its electron counterpart. In principle, angular momentum does not dictate DW motion since its governing dynamics, Landau-Lifshitz-Gilbert (LLG) equation, does not conserve the total angular momentum when the spin-lattice and spin-orbital interactions are involved. Nevertheless, all studies [13,14,16] showed that a DW propagates to the hotter part of a wire under a temperature gradient. Although this result is consistent with the STT prediction, magnonic STT cannot be the sole physics behind. It is thus * Corresponding author: phxw...

show abstract

mentioning

confidence: 99%

Thermodynamic theory for thermal-gradient-driven domain-wall motion

Wang

2014

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Joule heating when passing a spin-polarized current consisting of electrons through a device: current-densities of order 10 6 A/cm 2 are needed to perform magnetization switching via current-induced spin-transfer torque. As an alternative mechanism to spin-transfer torque which could circumvent the Joule heating from electrons, magnon-induced magnetization dynamics has been investigated more recently [4][5][6][7] .…”

Section: Introductionmentioning

confidence: 99%

Asymmetric ferromagnetic resonance, universal Walker breakdown, and counterflow domain wall motion in the presence of multiple spin-orbit torques

Linder

Alidoust

2013

Phys. Rev. B

View full text Add to dashboard Cite

We study the motion of several types of domain wall profiles in spin-orbit coupled magnetic nanowires and also the influence of spin-orbit interaction on the ferromagnetic resonance of uniform magnetic films. Whereas domain wall motion in systems without correlations between spin-space and real-space is not sensitive to the precise magnetization texture of the domain wall, spin-orbit interactions break the equivalence between such textures due to the coupling between the momentum and spin of the electrons. In particular, we extend previous studies by fully considering not only the field-like contribution from the spin-orbit torque, but also the recently derived Slonczewski-like spin-orbit torque. We show that the latter interaction affects both the domain wall velocity and the Walker breakdown threshold non-trivially, which suggests that it should be accounted in experimental data analysis. We find that the presence of multiple spin-orbit torques may render the Walker breakdown to be universal in the sense that the threshold is completely independent on the material-dependent Gilbert damping α, non-adiabaticity β, and the chirality σ of the domain wall. We also find that domain wall motion against the current injection is sustained in the presence of multiple spin-orbit torques and that the wall profile will determine the qualitative influence of these different types of torques (e.g. field-like and Slonczewski-like). In addition, we consider a uniform ferromagnetic layer under a current bias, and find that the resonance frequency becomes asymmetric against the current direction in the presence of Slonczewski-like spin-orbit coupling. This is in contrast with those cases where such an interaction is absent, where the frequency is found to be symmetric with respect to the current direction. This finding shows that spin-orbit interactions may offer additional control over pumped and absorbed energy in a ferromagnetic resonance setup by manipulating the injected current direction.

show abstract

“…This type of torque mediated by magnon-and/or spin-wave-spin current may find use in moving domain walls [179][180][181][182][183][184][185]. It is closely related to spin-dependent thermoelectric effects, such as spin-dependent Seebeck, Peltier, and Nernst effects [186][187][188][189].…”

Section: Discussionmentioning

confidence: 99%

Self-consistent calculation of spin transport and magnetization dynamics

et al. 2013

View full text Add to dashboard Cite

A spin-polarized current transfers its spin-angular momentum to a local magnetization, exciting various types of current-induced magnetization dynamics. So far, most studies in this field have focused on the direct effect of spin transport on magnetization dynamics, but ignored the feedback from the magnetization dynamics to the spin transport and back to the magnetization dynamics. Although the feedback is usually weak, there are situations when it can play an important role in the dynamics. In such situations, simultaneous, self-consistent calculations of the magnetization dynamics and the spin transport can accurately describe the feedback. This review describes in detail the feedback mechanisms, and presents recent progress in self-consistent calculations of the coupled dynamics. We pay special attention to three representative examples, where the feedback generates non-local effective interactions for the magnetization after the spin accumulation has been integrated out. Possibly the most dramatic feedback example is the dynamic instability in magnetic nanopillars with a single magnetic layer. This instability does not occur without non-local feedback. We demonstrate that full self-consistent calculations generate simulation results in much better agreement with experiments than previous calculations that addressed the feedback effect approximately.The next example is for more typical spin valve nanopillars. Although the effect of feedback is less dramatic because even without feedback the current can make stationary states unstable and induce magnetization oscillation, the feedback can still have important consequences. For instance, we show that the feedback can reduce the linewidth of oscillations, in agreement with experimental observations. A key aspect of this reduction is the suppression of the excitation of short wave length spin waves by the non-local feedback.Finally, we consider nonadiabatic electron transport in narrow domain walls. The non-local feedback in these systems leads to a significant renormalization of the effective nonadiabatic 3 spin transfer torque. These examples show that the self-consistent treatment of spin transport and magnetization dynamics is important for understanding the physics of the coupled dynamics and for providing a bridge between the ongoing research fields of current-induced magnetization dynamics and the newly emerging fields of magnetization-dynamics-induced generation of charge and spin currents.

show abstract

Magnetic domain-wall motion by propagating spin waves

Cited by 150 publications

References 24 publications

Thermodynamic theory for thermal-gradient-driven domain-wall motion

Thermodynamic theory for thermal-gradient-driven domain-wall motion

Asymmetric ferromagnetic resonance, universal Walker breakdown, and counterflow domain wall motion in the presence of multiple spin-orbit torques

Self-consistent calculation of spin transport and magnetization dynamics

Contact Info

Product

Resources

About