Instability of magnetic skyrmion strings induced by longitudinal spin currents
- Resource Type
- Working Paper
- Authors
- Okumura, Shun; Kravchuk, Volodymyr P.; Garst, Markus
- Source
- Phys. Rev. Lett. 131, 066702 (2023)
- Subject
- Condensed Matter - Mesoscale and Nanoscale Physics
Condensed Matter - Strongly Correlated Electrons
- Language
It is well established that spin-transfer torques exerted by in-plane spin currents give rise to a motion of magnetic skyrmions resulting in a skyrmion Hall effect. In films of finite thickness or in three-dimensional bulk samples the skyrmions extend in the third direction forming a string. We demonstrate that a spin current flowing longitudinally along the skyrmion string instead induces a Goldstone spin wave instability. Our analytical results are confirmed by micromagnetic simulations of both a single string as well as string lattices suggesting that the instability eventually breaks the strings. A longitudinal current is thus able to melt the skyrmion string lattice via a dynamical phase transition. For films of finite thickness or in the presence of disorder a threshold current will be required, and we estimate the latter assuming weak collective pinning.
Comment: 10 pages, 7 figures