Magnetization Dynamics in Vortex-Imprinted Ni $_{80}$ Fe $_{20}$ /Ir $_{20}$ Mn $_{80}$ Square Elements

摘要: The dynamic behavior of the vortex magnetization on micrometer-sized, ferromagnetic/antiferromagnetic (FM/AFM) bilayer exchange-coupled square elements is investigated using time-resolved Kerr effect microscopy and micromagnetic modeling. $10 \mu$ m $\times 10 consisting Ni $_{80}$ Fe $_{20}$ /Ir Mn bilayers were prepared subsequently field cooled at various strengths $H_{\rm cf}$ , resulting in different exchange-bias ex}$ profiles FM/AFM interface. With presence core displaced from center consequently fourfold symmetry Landau state breaks. spin-wave eigenmode excited upon application a magnetic pulse strongly dependent level displacement configuration, which mode frequency decreases for growing domain, whereas it increases shrinking domain.