The electronic structure and possible electronic orders in monolayer NbF4 are investigated by density functional theory and functional renormalization group.Because of the niobium-centered octahedra,the energy band ne...The electronic structure and possible electronic orders in monolayer NbF4 are investigated by density functional theory and functional renormalization group.Because of the niobium-centered octahedra,the energy band near the Fermi level is found to derive from the 4 dxyorbital,well separated from the other bands.Local Coulomb interaction drives the undoped system into an antiferromagnetic insulator.Upon suitable electron/hole doping,the system is found to develop dx2à-y2 wave superconductivity with sizable transition temperature.Therefore,the monolayer NbF4 may be an exciting 4d1 analogue of cuprates,providing a new two-dimensional platform for high-Tc superconductivity.展开更多
文摘铁基超导体是继铜氧化合物高温超导体之后于2008年被发现的一类新型高温超导材料.在所有铁基超导体中,β-Fe Se因具有最简单的化学组分和结构而被认为是探索超导机制的理想体系.借助于半导体工业中成熟的分子束外延生长技术,研究者实现了对Fe Se超导薄膜生长、形貌和组分在原子水平上的精确控制,并在此基础上深入研究了其超导性质.最近研究者又把Fe Se薄膜的分子束外延生长拓展到Sr Ti O3(001)衬底,发现单层Fe Se/Sr Ti O3体系的超导转变温度有超过77 K的迹象.这些研究成果为解决高温超导体的配对机制以及进一步提高超导转变温度提供了全新的途径和思路,引起高温超导和材料科学等领域的广泛关注.
基金the National Key Research and Development Program of China(2016YFA0300401)the National Natural Science Foundation of China(11604303,11604168 and 11574134)+1 种基金the Texas Center for Superconductivity at the University of Houston and the Robert A.Welch Foundation(E-1146)the support from China Scholarship Council(201909440001)。
文摘The electronic structure and possible electronic orders in monolayer NbF4 are investigated by density functional theory and functional renormalization group.Because of the niobium-centered octahedra,the energy band near the Fermi level is found to derive from the 4 dxyorbital,well separated from the other bands.Local Coulomb interaction drives the undoped system into an antiferromagnetic insulator.Upon suitable electron/hole doping,the system is found to develop dx2à-y2 wave superconductivity with sizable transition temperature.Therefore,the monolayer NbF4 may be an exciting 4d1 analogue of cuprates,providing a new two-dimensional platform for high-Tc superconductivity.
