Annihilation and control of chiral domain walls with magnetic fields*

The control of domain walls (DW) is central to nearly all magnetic technologies, particularly for information storage and spintronics. Creative attempts to increase storage density need to overcome volatility due to thermal and quantum fluctuations of nanoscopic domains and heating limitations. In contrast, topological defects, such as solitons, skyrmions, and merons, maybe much less susceptible to fluctuations, owing to topological constraints, while also being controllable with relatively low current densities. Here we present, the first evidence for soliton/soliton and soliton/antisoliton DW in a thin lamella of the hexagonal chiral magnet Mn_1/3NbS₂ that respond asymmetrically to small magnetic fields and exhibit pair-annihilation. This is important because it suggests that it may be possible to control the occurrence of soliton pairs and to make use of small fields or, more interestingly, small currents to control these nanoscopic magnetic domains. Specifically, our data suggest we can stabilize a state of either soliton/soliton or soliton/antisoliton pairs by tuning the balance between intrinsic exchange interactions and long-range magnetostatics in restricted geometries.