We report a transient plasmonic spin skyrmion topological quasiparticle within surface plasmon polariton vortices, which is described by analytical modeling and imaging of its formation by ultrafast interferometric time-resolved photoemission electron microscopy. Our model finds a twisted skyrmion spin texture on the vacuum side of a metal/vacuum interface and its integral opposite counterpart in the metal side. The skyrmion pair forming a hedgehog texture is associated with co-gyrating anti-parallel electric and magnetic fields, which form intense pseudoscalar E·B focus that breaks the local time-reversal symmetry and can drive magnetoelectric responses of interest to the axion physics. Through nonlinear two-photon photoemission, we record attosecond precision images of the plasmonic vectorial vortex field evolution with nanometer spatial and femtosecond temporal (nanofemto) resolution, from which we derive the twisted plasmonic spin skyrmion topological textures, their boundary, and topological charges; the modeling and experimental measurements establish a quantized integer photonic topological charge that is stable over the optical generation pulse envelope.

中文翻译：

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扭曲等离子体自旋斯格明子的超快显微镜

我们报告了表面等离子体激元涡流内的瞬态等离子体自旋斯格格子拓扑准粒子，通过超快干涉时间分辨光电子显微镜对其形成的分析建模和成像进行了描述。我们的模型在金属/真空界面的真空侧发现了扭曲的 skyrmion 自旋纹理，在金属侧发现了其完整的相对对应物。形成刺猬纹理的 skyrmion 对与共同旋转的反平行电场和磁场相关联，形成强烈的伪标量 E·B 焦点，打破了局部时间反转对称性，可以驱动对轴子物理感兴趣的磁电响应。通过非线性双光子光电发射，我们记录了具有纳米空间和飞秒时间 (nanofemto) 分辨率的等离子矢量涡旋场演化的阿秒精度图像，从中我们推导出扭曲的等离子自旋 skyrmion 拓扑结构、它们的边界和拓扑电荷；建模和实验测量建立了一个量化的整数光子拓扑电荷，它在光生成脉冲包络上是稳定的。