Real-space observations of 60-nm skyrmion dynamics in an insulating magnet under low heat flow.

Yu, Xiuzhen; Kagawa, Fumitaka; Seki, Shinichiro; Kubota, Masashi; Masell, Jan; Yasin, Fehmi S; Nakajima, Kiyomi; Nakamura, Masao et al. · Nat Commun · 2021

basic_science · Level V

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Abstract

Thermal-current induced electron and spin dynamics in solids -dubbed "caloritronics"- have generated widespread interest in both fundamental physics and spintronics applications. Here, we examine the dynamics of nanometric topological spin textures, skyrmions driven by a temperature gradient ∇T or heat flow, that are evaluated through in-situ real-space observations in an insulating helimagnet Cu<sub>2</sub>OSeO<sub>3</sub>. We observe increases of the skyrmion velocity and the Hall angle with increasing ∇T above a critical value of ~ 13 mK/mm, which is two orders of magnitude lower than the ∇T required to drive ferromagnetic domain walls. A comparable magnitude of ∇T is also observed to move the domain walls between a skyrmion domain and the non-topological conical-spin domain from cold to hot regions. Our results demonstrate the efficient manipulation of skyrmions by temperature gradients, a promising step towards energy-efficient "green" spintronics.