Topological spin textures such as magnetic skyrmions hold considerable promise as robust, nanometre-scale, mobile bits for sustainable computing. A longstanding roadblock to unleashing their potential is the absence of a device enabling deterministic electrical readout of individual spin textures. Here we present the wafer-scale realization of a nanoscale chiral magnetic tunnel junction (MTJ) hosting a single, ambient skyrmion. Using a suite of electrical and multi-modal imaging techniques, we show that the MTJ nucleates skyrmions of fixed polarity, whose large readout signal - 20-70% relative to uniform states - corresponds directly to skyrmion size. Further, the MTJ exploits complementary mechanisms to stabilize distinctly sized skyrmions at zero field, thereby realizing three nonvolatile electrical states. Crucially, it can write and delete skyrmions using current densities 1,000 times lower than state-of-the-art. These results provide a platform to incorporate readout and manipulation of skyrmionic bits across myriad device architectures, and a springboard to harness chiral spin textures for multi-bit memory and unconventional computing.
@article{arxiv.2302.08020,
title = {All-Electrical Skyrmionic Bits in a Chiral Magnetic Tunnel Junction},
author = {Shaohai Chen and Pin Ho and James Lourembam and Alexander K. J. Toh and Jifei Huang and Xiaoye Chen and Hang Khume Tan and Sherry K. L. Yap and Royston J. J. Lim and Hui Ru Tan and T. S. Suraj and Yeow Teck Toh and Idayu Lim and Jing Zhou and Hong Jing Chung and Sze Ter Lim and Anjan Soumyanarayanan},
journal= {arXiv preprint arXiv:2302.08020},
year = {2024}
}