Observation of Two-Level Critical State in the Superconducting FeTe Thin Films  

作　　者：Hao Ru Yi-Shi Lin Yin-Cong Chen Yang Feng Yi-Hua Wang 茹浩;林一石;陈寅聪;冯洋;王熠华(Department of Physics and State Key Laboratory of Surface Physics, Fudan University)

机构地区：[1]Department of Physics and State Key Laboratory of Surface Physics, Fudan University

出　　处：《Chinese Physics Letters》2019年第7期94-97,共4页中国物理快报（英文版）

基　　金：Supported by the National Key Research and Development Program of China under Grant Nos 2016YFA0301002 and 2017YFA0303000;the National Natural Science Foundation of China under Grant No 11827805

摘　　要：FeTe, a non-superconducting parent compound in the iron-chalcogenide family, becomes superconducting after annealing in oxygen. Under the presence of magnetism, spin-orbit coupling, inhomogeneity and lattice distortion,the nature of its superconductivity is not well understood. Here we combine the mutual inductance technique with magneto transport to study the magnetization and superconductivity of FeTe thin films. It is found that the films with the highest TC show non-saturating superfluid density and a strong magnetic hysteresis distinct from that in a homogeneous superconductor. Such a hysteresis can be well explained by a two-level critical state model and suggests the importance of granularity to superconductivity in this compound.FeTe, a non-superconducting parent compound in the iron-chalcogenide family, becomes superconducting after annealing in oxygen. Under the presence of magnetism, spin-orbit coupling, inhomogeneity and lattice distortion,the nature of its superconductivity is not well understood. Here we combine the mutual inductance technique with magneto transport to study the magnetization and superconductivity of FeTe thin films. It is found that the films with the highest T_C show non-saturating superfluid density and a strong magnetic hysteresis distinct from that in a homogeneous superconductor. Such a hysteresis can be well explained by a two-level critical state model and suggests the importance of granularity to superconductivity in this compound.

关 键 词：a non-superconducting iron-chalcogenide SUPERCONDUCTIVITY in this COMPOUND 

分 类 号：O4[理学—物理]