Topological Magnetic Textures Mediated Magnetocaloric Effect in Janus Monolayer

Topological magnetic textures (TMTs) such as skyrmions, merons, and vortices are promising for next-generation spintronic technology. Here, the prospect of TMTs in cooling technology is explored, and the influence of TMTs on magnetocaloric effect (MCE) in typical Janus monolayers (symmetry-broken VSi₂N₄ derivatives) that exhibit prominent Dzyaloshinskii–Moriya interaction (DMI) is specifically elaborated. It is found that the Janus monolayers VSi₂N₂P₂, VSi₂N₂As₂ and VSi₂NAs₃ allow for versatile TMTs including bimerons, meron pairs and skyrmions. Skyrmions and bimerons are demonstrated to remain stable up to 100 K. Under external magnetic fields, TMTs either experience shrinkage or exhibit a significant magnetization reversal. This results in TMTs-mediated MCE driven by topological magnetic-to-ferromagnetic phase transition, which intrinsically differs from the conventional MCE driven by paramagnetic-to-ferromagnetic phase transition. The TMTs-mediated MCE is revealed to benefit from a combination of pseudo-first-order and second-order phase transition and thus exhibit a broader operating temperature range. These findings offer an in-depth understanding on the role of TMTs in MCE of Janus monolayers and can inspire nanoscale 2D cooling science and technology.