All-Electrical Control of Chiral Spin Textures*

Topological spin textures such as magnetic skyrmions represent the smallest realizable emergent magnetic entities in functional materials [1]. Their ambient stability and ease of tunability in ultrathin magnetic films [2-3] has generated considerable promise as robust, nanometre-scale, mobile bits for sustainable computing [4]. 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 [5]. Using a suite of electrical and multi-modal imaging techniques, we show that the MTJ nucleates skyrmions of fixed polarity, whose large readout signal corresponds directly to skyrmion size. Further, the MTJ exploits complementary mechanisms to stabilize distinctly sized skyrmions at zero field, thereby realizing three non-volatile electrical states. Crucially, it can electrically write and delete skyrmions to both uniform states with switching energies 1,000 times lower than state-of-the-art. Here, the applied voltage emulates a magnetic field, and, in contrast to conventional MTJs, reshapes both the energetics and kinetics of the switching transition. Our stack platform enables large-readout, efficient switching, and lateral manipulation of skyrmionic bits [6], providing the much-anticipated backbone for all-electrical skyrmionic architectures. Its wafer-scale realisability provides a springboard to harness chiral spin textures for multi-bit memory and unconventional computing. 

[1] A. Soumyanarayanan et al., Nature Materials (2017) 16, 898.

[2] X. Chen et al., Advanced Science (2022) 9, 2103978.

[3] X. Chen et al., Advanced Functional Materials (2023) 2304560.

[4] A. Soumyanarayanan et al., Nature (2016) 539, 509.

[5] S. Chen, et al., ArXiv (2023) 2302.08020. 

[6] A.K.C. Tan et al., Nature Communications (2021) 12, 4252.