Antiferromagnets have several favourable properties as active elements in spintronic devices, including ultra-fast dynamics, zero stray fields and insensitivity to external magnetic fields1. Tetragonal CuMnAs is a testbed system in which the antiferromagnetic order parameter can be switched reversibly at ambient conditions using electrical currents2. In previous experiments, orthogonal in-plane current pulses were used to induce 90° rotations of antiferromagnetic domains and demonstrate the operation of all-electrical memory bits in a multi-terminal geometry3. Here, we demonstrate that antiferromagnetic domain walls can be manipulated to realize stable and reproducible domain changes using only two electrical contacts. This is achieved by using the polarity of the current to switch the sign of the current-induced effective field acting on the antiferromagnetic sublattices. The resulting reversible domain and domain wall reconfigurations are imaged using X-ray magnetic linear dichroism microscopy, and can also be detected electrically. Switching by domain-wall motion can occur at much lower current densities than those needed for coherent domain switching.
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We thank the Diamond Light Source for the allocation of beam time under Proposal no. SI16376-1. This work was supported by the Engineering and Physical Sciences Research Council (grant number EP/P019749/1), National Science Centre, Poland (grant 2016/21/N/ST3/03380), the Ministry of Education of the Czech Republic Grants no. LM2015087 and no. LNSM-LNSpin, the Czech National Science Foundation Grant no. 14-37427, the EU FET Open RIA Grant no. 766566 and the ERC Synergy Grant no. 610115. P.W. acknowledges support from the Royal Society through a University Research Fellowship.
Supplementary Figures 1–4; Supplementary Text; Supplementary References.