Room-temperature skyrmion lattice in a layered magnet (Fe <sub>0.5</sub> Co <sub>0.5</sub> ) <sub>5</sub> GeTe <sub>2</sub>
Hongrui Zhang, David Raftrey, Ying‐Ting Chan, Yu‐Tsun Shao, Rui Chen, Xiang Chen, Xiaoxi Huang, Jonathan Reichanadter, Kaichen Dong, Sandhya Susarla, Lucas Caretta, Zhen Chen, Jie Yao, Peter Fischer, Jeffrey B. Neaton, Weida Wu, David A. Muller, R. J. Birgeneau, R. Ramesh
Abstract
Novel magnetic ground states have been stabilized in two-dimensional (2D) magnets such as skyrmions, with the potential next-generation information technology. Here, we report the experimental observation of a Néel-type skyrmion lattice at room temperature in a single-phase, layered 2D magnet, specifically a 50% Co–doped Fe 5 GeTe 2 (FCGT) system. The thickness-dependent magnetic domain size follows Kittel’s law. The static spin textures and spin dynamics in FCGT nanoflakes were studied by Lorentz electron microscopy, variable-temperature magnetic force microscopy, micromagnetic simulations, and magnetotransport measurements. Current-induced skyrmion lattice motion was observed at room temperature, with a threshold current density, j th = 1 × 10 6 A/cm 2 . This discovery of a skyrmion lattice at room temperature in a noncentrosymmetric material opens the way for layered device applications and provides an ideal platform for studies of topological and quantum effects in 2D.