Current-induced dynamics of skyrmion strings

Tomoyuki Yokouchi, Shintaro Hoshino, Naoya Kanazawa, Akiko Kikkawa, Daisuke Morikawa, Kiyou Shibata, Taka hisa Arima, Yasujiro Taguchi, Fumitaka Kagawa, Naoto Nagaosa, Yoshinori Tokura

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Dynamics of string-like objects is an important issue in a broad range of physical systems, including vortex lines in superconductors, viscoelastic polymers, and superstrings in elementary particle physics. In noncentrosymmetric magnets, string forms of magnetic skyrmions are present as topological spin objects, and their current-induced dynamics has recently attracted intense interest. We show in the chiral magnet MnSi that the current-induced deformation dynamics of skyrmion strings results in transport response associated with the real-space Berry phase. Prominent nonlinear Hall signals emerge above the threshold current only in the skyrmion phase. We clarify the mechanism for these nonlinear Hall signals by adopting spin density wave picture to describe the moving skyrmion lattice; deformation of skyrmion strings occurs in an asymmetric manner due to the Dzyaloshinskii-Moriya interaction, which leads to the nonreciprocal nonlinear Hall response originating from an emergent electromagnetic field. This finding reveals the dynamical nature of string-like objects and consequent transport outcomes in noncentrosymmetric systems.

Original languageEnglish
Article numbereaat1115
JournalScience Advances
Volume4
Issue number8
DOIs
Publication statusPublished - 2018 Aug 10
Externally publishedYes

ASJC Scopus subject areas

  • General

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    Yokouchi, T., Hoshino, S., Kanazawa, N., Kikkawa, A., Morikawa, D., Shibata, K., Arima, T. H., Taguchi, Y., Kagawa, F., Nagaosa, N., & Tokura, Y. (2018). Current-induced dynamics of skyrmion strings. Science Advances, 4(8), [eaat1115]. https://doi.org/10.1126/sciadv.aat1115