The photonic spin Hall effect, a deep subdiffraction-limited shift between the opposite spin components of light, emerges when light undergoes an evolution of polarization or trajectory that induces the geometric phase. Here, we study a stochastic photonic spin Hall effect arising from space-variant Berry-Zak phases, which are generated by disordered magneto-optical effects. This spin shift is observed from a spatially bounded lattice of ferromagnetic meta-atoms displaying nanoscale disorders. A random variation of the radii of the meta-atoms induces the nanoscale fluctuation. The standard deviation of the probability distribution of the spin shifts is proportional to the fluctuation of the meta-atoms. This enables us to detect a five-nanometre fluctuation by measuring the probability distribution of the spin shifts via weak measurements. Our approach may be used for sensing deep-subwavelength disorders by actively breaking the photonic spin symmetry and may enable investigations of fluctuation effects in magnetic nanosystems.

中文翻译：

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用随机光子自旋霍尔效应探测铁磁亚原子的纳米级涨落。

光子自旋霍耳效应是光的相反自旋分量之间的一个深的亚衍射极限位移，当光经历偏振或轨迹的演化而引发几何相位时，就会出现光子自旋霍尔效应。在这里，我们研究由空间变异的Berry-Zak相引起的随机光子自旋霍尔效应，其由无序磁光效应产生。从显示纳米级无序的铁磁亚原子的空间有界晶格观察到这种自旋位移。准原子半径的随机变化会引起纳米级的波动。自旋位移概率分布的标准偏差与亚原子的波动成正比。这使我们能够通过弱测量来测量自旋位移的概率分布，从而检测出五纳米的波动。