铁砷基超导薄膜物理性质研究

项目名称： 铁砷基超导薄膜物理性质研究

项目编号： No.11474324

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 曹立新

作者单位： 中国科学院物理研究所

项目金额： 90万元

中文摘要： 铁砷基超导薄膜具有第二高的超导转变温度（56 K）、较长的相干长度、对称的超导波函数、较小的各向异性，因此比铜氧化物更适合于超导电子学应用。另外，铁砷基超导薄膜表现出不同于体材料的、特殊的物理性质，例如，不超导的母相在薄膜状态下由于应力效应出现超导。六年来的实践表明，如何制备高质量的薄膜仍然是亟待解决的首要问题。在前期研究工作中，我们研制了新型分子束辅助的脉冲激光沉积装备，初步得到了高质量的铁砷基122相超导薄膜、锌锰基122相稀磁半导体（DMS）薄膜。通过本项目，突破铁砷基超导、尤其是1111相超导薄膜制备的关键技术，开展一些以薄膜为特色的实验，包括应力效应、界面超导电性、多层膜的层间耦合、超导与DMS异质结的超导/铁磁界面的自旋注入和Andreev反射、约瑟夫森效应、磁通钉扎和磁通运动，等。测量一批与薄膜应用密切相关的本征的基本物理参数，为超导电子学应用打下基础。SCI文章8-10篇。

中文关键词： 铁基超导体；铁砷基超导体；薄膜；物理性质；表面和界面

英文摘要： Pocessing the second highest transition temperature (56 K), longer coherence length, symmetric order parameter (S+- wave), and much smaller anisotropy, the iron pnictide superconductor (IPSC) thin films are much more suitable than cuprate for superconducting electronic applications. Furthermore, it has been observed very recently that the IPSC thin films exibit very unique physical properties in comparison with their bulk counterparts, e.g., non-superconducting parent compound BaFe2As2 becomes superconducting in the form of thin films because of the strain effects. 6-years scientific research practices told us that how to obtain the high-quality thin films is still the top priority on the agenda of the IPSC thin film research. In our own pre-research, we studied on the new methodology for deposition of such hard-to-be-synthesized and easy-to-deteriorate thin films, and built a new equipment named molecular beam assisted pulsed laser deposition (MBAPLD). Based on this newly studied methodology and newly built equipment, we obtained preliminarily the high-quality thin films of the IPSC 122-phase as well as high-quality thin films of the recently found new dilute magnetic semiconductor (DMS) 122-phase. Supported by this NSFC project, we plan to solve the key technical problems the deposition of the IPSC thin film (especially the 1111-phase thin film) are facing, and to study systematically a set of distinguishing characteristics of the thin films, including the strain effects, the interfacial superconductivity, the interlayer coupling in multilayers, the spin injection and the Andreev reflection at the interface of the IPSC/DMS heterostructure, the Josephson effect, and the votex physics such as flux flow and the magnetic phase diagram, etc. We also plan to measure and accumulate a set of intrinsic paramters of the high-quality IPSC thin films, which can serve as the guide for future electronics applications. Publish 8-10 SCI papers.

英文关键词： iron based superconductors;iron pnictide superconductors;thin films;physical properties;surface and interface