Rare Earth-Transition Metal Alloys as Promising Materials for Small Skyrmions and Ultrafast Chiral Spin Texture Dynamics

Spintronics aims to understand and control spins on the nanoscale and should enable next-generation data storage and logic devices. One technological and scientific key challenge is to stabilize small spin textures and to manipulate them efficiently with high speeds [1-3]. Inspired by hard disk materials, research has primarily focused on ferromagnetic materials, but these materials show fundamental limits for speed and size [4-6], calling for radically different ideas [4-7].
Here, we demonstrate that compensated ferrimagnets are not affected by these limits. We realize a current-driven domain wall velocity of over 1 km/s near the angular momentum compensation temperature (T_A) and room-temperature stable skyrmions with minimum observed diameters approaching ~10 nm near magnetic compensation (T_M). We present theory explaining these observations and demonstrate that high-speed, high-density spintronics devices based on current-driven spin textures can be realized using materials where T_A and T_M are close together.

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