Current Switching of Topological Spin Chirality in the van der Waals Antiferromagnet Co_1/3TaS₂.

Abstract

Magnetic topology is central to modern quantum magnet, where spin chirality governs exotic spin winding, real-space Berry phase, and topological Hall effect. A key unresolved challenge is how to electrically switch topological spin chirality and its associated gauge flux, an essential requirement for manipulating its topological quantum properties. In this work, we propose and experimentally demonstrate the concept of current-switching spin chirality. We identify the new vdW antiferromagnet Co_1/3TaS₂ as an ideal platform, hosting a topological 3Q state with a minimum chirality cell, an ultrahigh skyrmion density, a non-centrosymmetric geometry, and a strong Berry curvature. We discover intrinsic self-torque-induced chirality switching within Co_1/3TaS₂, driven purely by current, without the need for heavy metals or a magnetic field, and with high energy efficiency. Our results establish a promising framework for electrically generating and controlling topological spin chirality, and demonstrate a practical route toward chiral spintronics. They can be naturally generalized to other skyrmion systems, offering new opportunities in symmetry control, topological manipulation, and spin-chirality-based quantum functionalities.