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Calendar: ALS Calendar
Title: ALS Special Seminar | Dr. A Thiaville (U Paris-Sud)
When: 11/11/2013 1:00 PM - 2:00 PM
Description: ALS Special Seminar

Monday, November 11, 2013
6-2202 Conf Rm
1:00 - 2:00pm

Host:
Peter Fischer

Presented by:
André Thiaville
Laboratoire de Physique des Solides, Université Paris-Sud, CNRS UMR 8502, 91405 Orsay, France

Title:
A new type of domain wall in ultrathin films: the Dzyaloshinskii domain wall

Abstract:
We have explored a new type of magnetic domain wall structure in ultrathin films with perpendicular anisotropy, as a consequence of the existence of a Dzyaloshinskii-Moriya interaction (DMI) due to the adjacent layers. This study was performed by numerical and analytical micromagnetics. The results show that these walls can, depending on the value of the DMI constant, move in stationary conditions at large velocities under large fields. These walls also show interesting properties of current-induced domain wall motion under the spin Hall effect. Even if, in statics, these walls look like Néel walls for large enough DMI (and have been known for some time [1]), this is the first full micromagnetic study of them, that reveals that their dynamics are unique. Thus we propose to call them Dzyaloshinskii domain walls [2].
I shall first describe the study of the dynamics of these walls in a 1D micromagnetic framework, and show that a simple collective coordinates model can be built to account for most of the physics of this case [1]. In a second step, I will describe the additional features revealed by considering the full (2D) dynamics, with strong domain wall tilt effects appearing for large DMI, and the development of an appropriately extended collective coordinates model [3].
This work opens naturally into the micromagnetic study of skyrmions in ultrathin films with structural inversion asymmetry [4].

[1] M. Heide, G. Bihlmayer, S. Blügel, Phys. Rev. B 78, 140403 (2012).
[2] A. Thiaville, S. Rohart, E. Jué, V. Cros and A. Fert, Europhys. Lett. 100, 57002 (2012).
[3] O. Boulle, S. Rohart, L.D. Buda-Prejbeanu, E. Jué, I.M. Miron, S. Pizzini, J. Vogel, G. Gaudin, A. Thiaville, submitted to Phys. Rev. Lett., arxiv:1308.1824.
[4] S. Rohart, A. Thiaville, submitted to Phys. Rev. B, arxiv:1310.0666.
Location: 6-2202-CR(20)
Author: Adriana Reza