Precessing vortices and antivortices in ferromagnetic elements

反铁电体PbZrO3中的涡旋与反涡旋

Vortices and antivortices in antiferroelectric PbZrO3

本研究通过球差校正扫描透射电子显微镜在反铁电体PbZrO3的铁弹畴壁中发现了原子尺度涡旋与反涡旋，并结合深度学习势模拟和连续场建模揭示其物理机制，将手性拓扑研究拓展至反铁电体。

Symmetry Violation in a Superconducting Film with a Square Array of Ferromagnetic Dots

We study the equilibrium state of a superconducting film covered with a regular square array of perpendicularly magnetized magnetic dots. The dots induce vortices in the film directly under them and antivortices between the dots. We show that the symmetry of the dot array is spontaneously violated by the vortices. The positions of the vortices and the antivortices depend on the magnetization and the size of the dots.

The London Study of Vortex States in a Superconducting Film Due to a Magnetic Dot

Here we report a study of vortex states in a thin superconducting film with a magnetic dot grown upon it by means of a method based on London-Maxwell equations. Vortices with single quantum flux ($Φ_0 = h c / 2 e$), giant vortices (vortices with multiple flux) as well as antivortices (vortices with negative vorticity) are taken into consideration. It turns out that giant vortices occur, when the dot's size is sufficiently smaller ($R \leq 4.5 ξ$) than the effective penetration depth $Λ$. In the case of a dot with sufficiently large size ($R \geq 6 ξ$), the vortices with single quantum flux dom…

Unfolding of vortices into topological stripes in a multiferroic material

Multiferroic hexagonal RMnO3 (R=rare earths) crystals exhibit dense networks of vortex lines at which six domain walls merge. While the domain walls can be readily moved with an applied electric field, the vortex cores were so far impossible to control. Our experiments demonstrate that shear strain induces a Magnus-type force pulling vortices and antivortices in opposite directions and unfolding them into a topological stripe domain state. We discuss the analogy between this effect and the current-driven dynamics of vortices in superconductors and superfluids.

Analytic Property of Vortex-Type Spin Structures in Itinerant Electron System with Inversion Symmetry

Analytic properties of the multiple spin density waves showing vortex structures, which have recently been found in the fcc Hubbard model using the generalized Hartree-Fock (GHF) approximation, have been investigated. It is shown that the 2Q multiple helical spin density waves (SDW) consist of two types of half-skyrmion vortices and two types of antivortices. In the 3Q multiple helical SDW, the half-skyrmion vortex structures with the "westerlies" are shown to be twisted along the axis perpendicular to the vortex plane. The 12Q multiple SDW (12QMSDW) are analyzed as a superposition of the 2-4Q…

Symmetry Theory of the Flexomagnetoelectric Interaction in the Magnetic Vortices and Skyrmions

Symmetry classification of the magnetic vortices and skyrmions has been suggested. Relation between symmetry based predictions and direct calculation has been shown. It was shown, that electric dipole moment of the vortex is located inside the small vortex core. The antivortices and antiskyrmions do not carry the total core electric dipole induced by the flexomagnetoelectric interaction in the hexoctahedral cubic crystal. The volumetric bound electric charge is distributed around the core. Switching of the core electric dipole direction produces the switching of the core magnetization or vorte…