论文标题
在超薄铁摩 - 超导中观察二维超导性
Observation of Two-dimensional Superconductivity in an Ultrathin Iron-Arsenic Superconductor
论文作者
论文摘要
二维（2D）超导体提供了重要的平台，以探索新的量子物理和高$ T_C $超导率。由于制备超薄样品的困难，二维铁 - 摩西超导体中的固有超导特性仍然未知。在这里，我们报告了对铁疗法超导体KCA $ _2 $ fe $ _4 $ as $ _4 $ f $ _2 $的高质量单晶超薄膜的制造和物理调查。对于厚度为2.6 $ \ sim $ 5 nm（1 $ \ sim $ 2单元单元）的样品，观察到在30 K（起点）左右的急剧超导过渡。与散装材料相比，超薄样品显示出相对较低的$ t_c $，更宽的过渡宽度以及平面内字段下更宽的通量液体区域。此外，角度依赖的上临界场遵循Tinkham模型，展示了Ultrathin kca $ _2 $ fe $ _4 $ as $ _4 $ f $ _2 $中的二维超导率。
Two-dimensional (2D) superconductors supply important platforms for exploring new quantum physics and high-$T_c$ superconductivity. The intrinsic superconducting properties in the 2D iron-arsenic superconductors are still unknown owing to the difficulties in the preparation of ultrathin samples. Here we report the fabrication and physical investigations of the high quality single-crystalline ultrathin films of the iron-arsenic superconductor KCa$_2$Fe$_4$As$_4$F$_2$. For the sample with the thickness of 2.6$\sim$5 nm (1$\sim$2 unit cells), a sharp superconducting transition at around 30 K (onset point) is observed. Compare with the bulk material, the ultrathin sample reveals a relatively lower $T_c$, wider transition width, and broader flux liquid region under the in-plane field. Moreover, the angle dependent upper critical field follows the Tinkham model, demonstrating the two-dimensional superconductivity in ultrathin KCa$_2$Fe$_4$As$_4$F$_2$.
