# Simulation Study of Dynamic Rotation and Deformation for Plasmonic Electric Field-Skyrmions
## 1 Introduction  
Skyrmions, as a topological defect, were described by [PERSON] [1]. In the last ten years, the magnetic skyrmion has rapidly developed due to its valuable properties (possibilities for application in spintronic devices [2]; high speed [3]; and low-current drives [4]). The integer and semi-integer of stable and topological spin structures [5] have been proposed for the Dzyaloshinskii - Moriya interaction [6]. Since evanescent-field optical skyrmions were generated by plasmonic gratings [7], the research on optical skyrmions in structured light fields [8] has begun.  
Recently, the research on optical skyrmions has mainly focused on the theoretical level [9]. In addition to electric field vectors [10], stokes vectors [11] and transverse spin vectors [12] can be used similarly as objects to construct robust skyrmion structures and even to realize high-order forms such as hopfions [13]. When considering the spin \(-\)orbit interaction [14], the transverse spin texture of the plasmonic vortex can form a meron-like skyrmion [15]. However, such an optical skyrmion mostly exists in the form of a Neel type accompanied by a skyrmion number of 1 when the SOI (spin\(-\)orbit interaction) disappears [16]. For example, skyrmion arrays in SPP (surface plasmon polariton) fields have been excited by gratings [17], a high-spatiotemporal-resolution electric field vectordistribution obtained through the use of 2 PEEM (two-photon emission electron microscopy) technology [10], and skyrmions regulated in the field of graphene surfaces [18].  
SPP is the metal/dielectric surface's evanescent field and electromagnetic composite field [19]. Through [PERSON]'s equations, spin vectors perpendicular to the propagation direction are generated in the energy flow [20]. The electric field of SPP always undergoes polarity reversal in the plane where SPP waves propagate due to the presence of the imaginary component in the vertical direction [21], which is the cause of the Neel-type skyrmion configuration of the interference field. Therefore, to construct stable arrays, skyrmion regulation is limited to linear directional movements.  
Considering the possibilities of SPP-field skyrmion topological transformation [22] and the ability to achieve angular rotation and even more and free deformations for new topological types, we propose a structure, which has 12 arc-shaped slits hollowed out on the surface of the metal Ag; each slit is vertically excited with focused Gaussian, linearly polarized focused spots and is given the flexible phase. Through our simulation in FDTD (FDTD Solutions 2016a), we combined the rotations and deformations of skyrmions in the local plane, and the results showed two types of regulation that have independence and synthesizability, which are related to the positions and phase difference of incident Gaussian spots, respectively. This work provides powerful supplements to the field of optical skyrmions and improves the topological properties of electric fields under the tight coupling conditions of SPP fields. Significant application prospects have been demonstrated in fields such as high-density storage [23] and quantum communication [24].