Simulations Predict a Way to Stabilize and Control the Elusive Emergent Magnetic Monopole in Nanostructures

In an article that was published in Physical Review B, Michalis Charilaou predicts that individual Bloch points, emergent magnetic monopoles with vanishing local magnetization, can be created and stabilized by magnetostatic and chiral interactions in nanocuboids, confined in between two chiral bobbers of opposing polarity. The Bloch point can be driven by an external magnetic field reversibly, in a direction opposing the field, and it remains stable up to moderate field strengths. At a critical field strength, the Bloch point escapes through one of the surfaces, leaving behind a collinear magnetization configuration, and upon removing the field a new Bloch point is formed. These findings highlight the topological diversity in nanostructures and show that a Bloch point, despite its zero dimensionality, couples to external fields via a substantial magnetic volume around it. The control of topological point defects has technological implications with regards to reversibly movable nanomagnetic textures and their associated emergent electrodynamics.