论文标题
Sriro3/srruo3 perovskite Bilayer中的纳米级néel天空的旋转偏光stm成像
Spin polarized STM imaging of nanoscale Néel skyrmions in an SrIrO3/SrRuO3 Perovskite Bilayer
论文作者
论文摘要
自旋偏振扫描隧道显微镜（SPSTM）用于直接对SRIRO3 / srRRUO3双层系统中纳米级néelSkyrmions进行成像，该系统是迄今为止在任何系统中报告的最小的。使用氧化磁铁的外轴斑点溅射用于将氧化物Ferromagnet SRO的外延膜与SRIRO3的2个单位细胞限制，旨在提供界面旋转轨道耦合。原子分辨率STM成像和隧道光谱法用于鉴定裸露的SRRUO3的岛状Sriro3晶粒和小区域。仅在薄膜的SRIRO3覆盖区域中观察到孤立的天空，并表现出尺寸和形状的分布，平均直径为3 nm。我们发现，天空必须完全包含，但可能比任何给定的SRIRO3区域都小。此外，在不同厚度的sriro3岛上观察到了天际，而不会损失SPSTM对比度，这表明磁纹理位于Sriro3岛内，而不是基础的铁磁SRRRUO3。密度功能理论的计算表明，这可能是由于SRIRO3膜中与IRO层相关的诱导磁矩很小。
Spin-polarized scanning tunneling microscopy (SPSTM) was used to directly image nanoscale Néel skyrmions in a SrIrO3 / SrRuO3 bilayer system that are among the smallest reported to date in any system. Off-axis magnetron sputtering was used to cap epitaxial films of the oxide ferromagnet SRO with 2 unit cells of SrIrO3, intended to provide interfacial spin orbit coupling. Atomic resolution STM imaging and tunneling spectroscopy were used to identify island-like SrIrO3 grains and small regions of bare SrRuO3. Isolated skyrmions were only observed in SrIrO3-covered regions of the film, and exhibited a distribution of sizes and shapes with an average diameter of 3 nm. We found that skyrmions must be fully contained within, but may be smaller than, any given SrIrO3 region. Additionally, skyrmions were observed on SrIrO3 islands of varying thickness without loss of SPSTM contrast, suggesting the magnetic texture lies within the SrIrO3 island rather than the underlying ferromagnetic SrRuO3. Density functional theory calculations suggest this could be due to a small induced magnetic moment associated with IrO layers in the SrIrO3 film.
