We investigate the effect of the Dzyaloshinskii-Moriya interaction (DMI) on magnetic domain nucleation in a ferromagnetic thin film with perpendicular magnetic anisotropy. We propose an extended droplet model to determine the nucleation field as a function of the in-plane field. The model can explain the experimentally observed nucleation in a Co/Ni microstrip with the interfacial DMI. The results are also reproduced by micromagnetic simulation based on the string model. The electrical measurement method proposed in this study can be widely used to quantitatively determine the DMI energy density. Chiral spin textures, such as a skyrmion and a Néel type magnetic domain wall (DW), which are formed in perpendicularly magnetized ferromagnet (FM)/non-magnet (NM) structures, have attracted considerable attention for future spintronic devices that can perform massive and high-speed data processing with low power consumption [1-7].Lack of structural inversion symmetry with strong spin-orbit coupling at the FM/NM interface results in the Dzyaloshinskii-Moriya interaction (DMI) which results in chirality in spin textures [8][9][10]. In recent years, it has been experimentally demonstrated that skyrmion-like bubble domains can be formed stably at room temperature [11][12] and driven along a magnetic nanowire at a velocity of ~100 m/s [13,14]. In addition, a

Chiral spin textures of a ferromagnetic layer in contact to a heavy non-magnetic metal, such as Néel-type domain walls and skyrmions, have been studied intensively because of their potential for future nanomagnetic devices. The Dyzaloshinskii–Moriya interaction (DMI) is an essential phenomenon for the formation of such chiral spin textures. In spite of recent theoretical progress aiming at understanding the microscopic origin of the DMI, an experimental investigation unravelling the physics at stake is still required. Here we experimentally demonstrate the close correlation of the DMI with the anisotropy of the orbital magnetic moment and with the magnetic dipole moment of the ferromagnetic metal in addition to Heisenberg exchange. The density functional theory and the tight-binding model calculations reveal that inversion symmetry breaking with spin–orbit coupling gives rise to the orbital-related correlation. Our study provides the experimental connection between the orbital physics and the spin–orbit-related phenomena, such as DMI.

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We theoretically and numerically investigate magnetic domain wall dynamics in a nanowire of easy-cone magnet. The easy-cone domain wall exhibits several distinguishing dynamic features in comparison to the easy-axis domain wall. The features of easy-cone domain wall are related to the generation of additional chiral spin textures due to the domain wall precession, which is common for various driving sources such as magnetic fields and spin-transfer torques.The unique easy-cone domain wall dynamics could enrich magnetic domain wall study and find use in device applications based on easy-cone domain walls.

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