Observation of Two-dimensional Superconductivity in an Ultrathin Iron-Arsenic Superconductor
arXiv:2006.03338 · doi:10.1088/2053-1583/abdaba
Abstract
Two-dimensional (2D) superconductors supply important platforms for exploring new quantum physics and high- 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 KCaFeAsF. For the sample with the thickness of 2.65 nm (12 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 , 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 KCaFeAsF.
5 pages, 4 figures
References in corpus (9)
- Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
- Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd)
- Highly crystalline 2D superconductors
- High-temperature interface superconductivity between metallic and insulating cuprates
- Superconductivity in KCaFeAsF with Separate Double FeAs Layers
- High-T_c superconductivity in ultrathin Bi_2Sr_2CaCu_2O_8+x down to halfunit-cell thickness by protection with graphene
- Evidence for Helical Hinge Zero Modes in an Fe-Based Superconductor
- Single-crystal growth and extremely high H_c2 of 12442-type Fe-based superconductor KCa_2Fe_4As_4F_2
- Strong Pauli paramagnetic effect in the upper critical field of KCaFeAsF