铁基铁磁超导体的化学掺杂与物性研究

项目名称： 铁基铁磁超导体的化学掺杂与物性研究

项目编号： No.11474252

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： 曹光旱

作者单位： 浙江大学

项目金额： 100万元

中文摘要： 超导与铁磁是凝聚态系统中两种截然不同、相互对立的多体合作现象。两者共存于同一种材料（称之为铁磁超导体）可能产生多种新奇物理性质，例如：自发磁通涡旋态、FFLO态、隐铁磁性（cryptoferromagnetism）以及稠密磁畴结构等。近年来我们发现的铁基铁磁超导体为超导与铁磁的共存研究提供了良好的研究平台。本项目主要以掺杂EuFe2As2体系为研究对象，通过化学掺杂有效调节FeAs层内禀超导电性参数以及Eu铁磁层的内磁场，研究超导与铁磁共存的条件和原因；通过对典型的、高质量单晶样品的电输运性质、磁性质以及热学性质的全面测量和细致分析，揭示超导与铁磁共处的方式。重点研究超导与铁磁共存区可能的自发磁通涡旋、反常Nernst 效应与反常Hall 效应等铁磁超导体所特有的现象。本项目的实施不但可以进一步认识铁磁超导体，同时也为铁基铁磁超导体的可能应用打下一定的科学基础。

中文关键词： 铁基超导体；化学掺杂；物理性质

英文摘要： Superconductivity and ferromagnetism are two completely different and antagonistic many-body collective phenomena in condensed matter systems. Coexistence of the two phenomena in a single material (called ferromagnetic superconductors) may produce various novel physical properties, such as spontaneous vortex state, FFLO state, cryptoferromagnetism, dense magnetic domains, etc. The newly discovered iron-based ferromagnetic superconductors have provided a good platform for studying the coexistence of superconductivity and ferromagnetism. We will mainly study the doped EuFe2As2 system. By effectively tuning the intrinsic superconducting parameters of the FeAs layers and the internal field of the Eu sublattice, through suitable chemical doping, the condition and the reason for the coexistence will be able to be understood. In addition, with full measurements of electrotransport, magnetic and thermal properties on the typical and high-quality single crystals, the way of the coexistence will also be revealed. We will focus on the characteristic phenomena such as possible spontaneous vortex state, anomalous Nernst effect and Hall effect. This project is expected to further understand the interplay of superconductivity and magnetism in ferromagnetic superconductors and, moreover, to pave the way for the possible applications of the ferromagnetic superconductors.

英文关键词： Iron-based Superconductors;Chemical Doping;Physical Properties