# Current-induced rotational torques in the skyrmion lattice phase of chiral magnets

## Abstract

In chiral magnets without inversion symmetry, the magnetic structure can form a lattice of magnetic whirl lines, a two-dimensional skyrmion lattice, stabilized by spin-orbit interactions in a small range of temperatures and magnetic fields. The twist of the magnetization within this phase gives rise to an efficient coupling of macroscopic magnetic domains to spin currents. We analyze the resulting spin-transfer effects, and, in particular, focus on the current-induced rotation of the magnetic texture by an angle. Such a rotation can arise from macroscopic temperature gradients in the system as has recently been shown experimentally and theoretically. Here we investigate an alternative mechanism, where small distortions of the skyrmion lattice and the transfer of angular momentum to the underlying atomic lattice play the key role. We employ the Landau-Lifshitz-Gilbert equation and adapt the Thiele method to derive an effective equation of motion for the rotational degree of freedom. We discuss the dependence of the rotation angle on the orientation of the applied magnetic field and the distance to the phase transition.

- Authors:

- Institute of Theoretical Physics, University of Cologne, D-50937 Cologne (Germany)
- Institute for Theoretical Physics, Utrecht University, NL-3584 CE Utrecht (Netherlands)

- Publication Date:

- OSTI Identifier:
- 21596843

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review. B, Condensed Matter and Materials Physics

- Additional Journal Information:
- Journal Volume: 84; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevB.84.064401; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHIRALITY; DEGREES OF FREEDOM; EQUATIONS OF MOTION; L-S COUPLING; MAGNETIC FIELDS; MAGNETIZATION; MAGNETS; PHASE TRANSFORMATIONS; SIMULATION; SPIN; SYMMETRY; TEMPERATURE GRADIENTS; TORQUE; TWO-DIMENSIONAL CALCULATIONS; ANGULAR MOMENTUM; COUPLING; DIFFERENTIAL EQUATIONS; EQUATIONS; EQUIPMENT; INTERMEDIATE COUPLING; PARTIAL DIFFERENTIAL EQUATIONS; PARTICLE PROPERTIES

### Citation Formats

```
Everschor, Karin, Garst, Markus, Rosch, Achim, and Duine, R. A..
```*Current-induced rotational torques in the skyrmion lattice phase of chiral magnets*. United States: N. p., 2011.
Web. doi:10.1103/PHYSREVB.84.064401.

```
Everschor, Karin, Garst, Markus, Rosch, Achim, & Duine, R. A..
```*Current-induced rotational torques in the skyrmion lattice phase of chiral magnets*. United States. doi:10.1103/PHYSREVB.84.064401.

```
Everschor, Karin, Garst, Markus, Rosch, Achim, and Duine, R. A.. Mon .
"Current-induced rotational torques in the skyrmion lattice phase of chiral magnets". United States. doi:10.1103/PHYSREVB.84.064401.
```

```
@article{osti_21596843,
```

title = {Current-induced rotational torques in the skyrmion lattice phase of chiral magnets},

author = {Everschor, Karin and Garst, Markus and Rosch, Achim and Duine, R. A.},

abstractNote = {In chiral magnets without inversion symmetry, the magnetic structure can form a lattice of magnetic whirl lines, a two-dimensional skyrmion lattice, stabilized by spin-orbit interactions in a small range of temperatures and magnetic fields. The twist of the magnetization within this phase gives rise to an efficient coupling of macroscopic magnetic domains to spin currents. We analyze the resulting spin-transfer effects, and, in particular, focus on the current-induced rotation of the magnetic texture by an angle. Such a rotation can arise from macroscopic temperature gradients in the system as has recently been shown experimentally and theoretically. Here we investigate an alternative mechanism, where small distortions of the skyrmion lattice and the transfer of angular momentum to the underlying atomic lattice play the key role. We employ the Landau-Lifshitz-Gilbert equation and adapt the Thiele method to derive an effective equation of motion for the rotational degree of freedom. We discuss the dependence of the rotation angle on the orientation of the applied magnetic field and the distance to the phase transition.},

doi = {10.1103/PHYSREVB.84.064401},

journal = {Physical Review. B, Condensed Matter and Materials Physics},

issn = {1098-0121},

number = 6,

volume = 84,

place = {United States},

year = {2011},

month = {8}

}