Magneto-Seebeck microscopy of domain switching in collinear antiferromagnet CuMnAs
T. Janda, J. Godinho, T. Ostatnicky, E. Pfitzner, G. Ulrich, A. Hoehl, S. Reimers, Z. Šobáň, T. Metzger, H. Reichlová, V. Novák, R. P. Campion, J. Heberle, P. Wadley, K. W. Edmonds, O. J. Amin, J. S. Chauhan, S. S. Dhesi, F. Maccherozzi, R. M. Otxoa, P. E. Roy, K. Olejník, P. Němec, T. Jungwirth, B. Kaestner, J. Wunderlich
Abstract
The authors introduce a novel microscopy for antiferromagnetic nanostructures based on the local generation and detection of photocurrents, and apply it to the collinear and fully compensated antiferromagnet CuMnAs. By using the optical near field generated by a scattering near-field microscope, they display narrow 180${}^{\ensuremath{\circ}}$ domain walls (DWs) and provide the first experimental evidence of reversible current-pulse-driven 180${}^{\ensuremath{\circ}}$ DW displacements in agreement with theoretically predicted N\'eel spin-orbit torque DW motion. In CuMnAs, photocurrents result from the local magneto-Seebeck effect (MSE). MSE-based microscopy can be applied to the entire class of conductive antiferromagnets, and in contrast to the established X-ray linear dichroism microscopy which is based on large scale synchrotrons, it can be easily performed with common laboratory equipment.