The electrical footprint of antiskyrmions in crystalline mesoscale structures.

Heusler compounds have huge potential for applications in spintronics due to a high tunability of their electronic properties. Mn_1.4PtSn is a Heusler magnet with tetragonal, non-centrosymmetric crystal structure that hosts ferro- and antiferromagnetic, as well as strong Dzyaloshinskii-Moriya interactions. These are the key-ingredients for the presence of antiskyrmions (ASKs). Recently, ASKs were identified, even above room temperature, by Lorentz transmission microscopy (LTEM) in thin electron-transparent samples. Magnetic force microscopy revealed an almost linear dependence between the sample thickness and size of the spin textures. Owing to their topological nature, ASKs are expected to cause a topological Hall effect (THE). To date a direct detection of the THE from ASKs has been missing. We therefore investigated electrical transport in mesoscale structures fabricated by the application of focused ion beams (FIB) from high-quality single crystals of Mn_1.4PtSn. We combined magnetosensitive microscopy and electrical transport measurements. We were able to directly detect the THE as the ASK lattice emerges and demonstrate how it is effected by means of sample dimensions, temperature and field orientation.