A variety of nontrivial spin textures can appear on the nanoscale as a result of competing magnetic interactions. A notable example being studied actively at present is the Dzyaloshinskii‐Moriya interaction (DMI), which results from spin-orbit coupling and chiral symmetry breaking in thin films and multilayers [1,2]. The DMI not only confers a preferred handedness to spin configurations such as domain walls [3] and skyrmions [4], but it also influences how excitations like spin waves propagate within a material.
I will describe some recent theoretical work on how the DMI influences dynamical magnetization processes in ultrathin films. In particular, I will discuss how nonreciprocity and focusing effects can occur for spin waves in continuous films [5] and within chiral domain walls [6]. I will also present novel features involving skyrmion and antiskyrmion dynamics [7], where pair generation processes result in excess skyrmion charges. Such systems represent an interesting playground in which we can probe how matter/antimatter asymmetry arises between topological magnetic charges.
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[3] J.-P. Tetienne et al., Nat. Commun. 6, 6733 (2015).
[4] S. Heinze et al., Nat. Phys. 7, 713 (2011).
[5] J.-V. Kim, R. L. Stamps, and R. E. Camley, Phys. Rev. Lett. 117, 197204 (2016).
[6] F. Garcia-Sanchez et al., Phys. Rev. Lett. 114, 247206 (2015).
[7] U. Ritzmann et al., Nat. Electron. 1, 451 (2018).
Centre de Nanosciences et de Nanotechnologies, CNRS, Université Paris-Sud, Université Paris-Saclay