新型稀土超导电子材料反常物理性质研究

The rare-earth superconductor materials, such as heavy fermion superconductors CexLa1-xCoIn5, iron-based superconductors RFeAsO1xFx(R is rare-earth elements), have the localized 4f electrons. The competition between the Kondo screening effect and the superconductivity makes these superconducting materials display many unique physical properties, such as superconducting reentrance, superconductivity and antiferromagnetism coexistence, hide ordering and so on. Thus, it has been one of the hot research directions to explore the abnormal electronic states characters of the rare-earth superconductor materials in condensed mater physics, materials science and microelectronics fields.. This project aims to investigate the electronic structure and superconducting properties of the rare-earth superconducting functional electronic materials by the improved DFT+DMFT and DFT+Gutzwiller methods. The influence of the doping elements and their doping concentrations on the superconducting properties, the physical mechanisms and the superconducting phase diagrams will be explored. Our purpose is to design the rare-earth superconducting electronic materials with excellent performances, such as higher superconducting transition temperature and higher critical magnetic field, by manipulating the doping elements and their doping concentrations. These investigations will provide fruitful insights for further exploring and utilizing these materials.

稀土超导电子材料(如重费米子超导体CexLa1-xCoIn5、铁基超导体RFeAsO1xFx(R为稀土元素)等)中由于存在局域的4f电子, 其Kondo屏蔽效应和超导电性相互竞争，从而使得稀土超导电子材料表现出许多奇特的物理性质，例如超导重入、超导-反铁磁共存、隐藏序等丰富的物理现象。对其反常电子态性质的研究是目前凝聚态物理物理学、材料科学和微电子学等领域的前沿研究方向之一。. 本项目拟通过改进DFT+DMFT和DFT+Gutzwiller计算方法，深入研究各种不同的稀土超导功能电子材料，探索体系相应的电子结构、超导性质，解明相应反常性质的物理机制，获得其超导相图。本项目旨在通过控制掺杂元素和掺杂浓度，设计获得具有优异性能（例如较高的超导转变温度和较高的临界磁场等等）的稀土超导电子材料，为其进一步的实验研究和开发利用此类材料奠定理论基础。

对稀土电子材料反常电子态性质的研究是目前凝聚态物理物理学、材料科学和微电子学等领域的前沿研究方向之一。本项目采用第一性原理计算方法和动力学平均场相结合的方法，系统研究了不同元素替代，以及不同掺杂浓度情况下相应的电子结构和物理性质变化情况；在此基础上通过对材料的电、磁性质的深入研究，探索体系自旋相关的新性质；结合电子态密度、能带结构等性质的数值计算，归纳总结出这类体系共同的特征，解明稀土元素对体系的影响；解明稀土材料中的稀土元素种类和浓度等对电子性质的影响机理。本项目的研究为实现稀土电子材料在电子器件中的实际应用奠定理论基础。项目执行期间，项目组发表10篇SCI检索学术论文，包括Appl. Phys. Lett., J. Phys. Chem. C, J. Chem. Phys., J. Mater. Chem. C, Sci. Rep.等。