Anisotropic superconductivity in the spin-vortex antiferromagnetic superconductor CaK(Fe0.95Ni0.05)(4)As-4

Article

关键词: TOTAL-ENERGY CALCULATIONS;    BAND-STRUCTURE;    DENSITY-WAVE;    ORDER;    DYNAMICS;   

DOI  :  10.1103/PhysRevB.103.L060506

来源: SCIE

【 摘 要 】

High critical temperature superconductivity often occurs in systems where an antiferromagnetic order is brought near T = 0 K by slightly modifying pressure or doping. CaKFe4As4 is a superconducting, stoichiometric iron-pnictide compound showing optimal superconducting critical temperature with T-c as large as 35 K. Doping with Ni induces a decrease in T-c and the onset of spin-vortex crystal (SVC) antiferromagnetic order, which consists of spins pointing inwards to or outwards from alternating As sites on the diagonals of the in-plane square Fe lattice. Here we study the band structure of CaK(Fe0.95Ni0.05)(4)As-4 T-c = 10 K, T-SVC = 50 K) using quasiparticle interference with a scanning tunneling microscope and show how the SVC modifies the band structure and induces a fourfold superconducting gap anisotropy.

【 授权许可】

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