Current-induced viscoelastic topological unwinding of metastable skyrmion strings
説明
<jats:title>Abstract</jats:title><jats:p>In the MnSi bulk chiral magnet, magnetic skyrmion strings of 17 nm in diameter appear in the form of a lattice, penetrating the sample thickness, 10–1000 μm. Although such a bundle of skyrmion strings may exhibit complex soft-matter-like dynamics when starting to move under the influence of a random pinning potential, the details remain highly elusive. Here, we show that a metastable skyrmion-string lattice is subject to topological unwinding under the application of pulsed currents of 3–5 × 10<jats:sup>6</jats:sup> A m<jats:sup>–2</jats:sup> rather than being transported, as evidenced by measurements of the topological Hall effect. The critical current density above which the topological unwinding occurs is larger for a shorter pulse width, reminiscent of the viscoelastic characteristics accompanying the pinning-creep transition observed in domain-wall motion. Numerical simulations reveal that current-induced depinning of already segmented skyrmion strings initiates the topological unwinding. Thus, the skyrmion-string length is an element to consider when studying current-induced motion.</jats:p>
収録刊行物
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- Nature Communications
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Nature Communications 8 (1), 1332-, 2017-11-06
Springer Science and Business Media LLC
