Observation of magnetic flux quantum in Fe(Te, Se) thin film deposited on a CaF2 single crystalline substrate

金グラシア, 井上昌睦, 今村和孝, 東川甲平, 木須隆暢（九大）； BRACCINI Valeria, BELLINGERI Emilio, PUTTI Marina （CNR-SPIN Genova）

Abstract: It is well established that electromagnetic properties in practical type II superconductor is governed by the magnetic flux quantum in superconductor. In the new series of iron based superconductors, however, fluxoid dynamics in mesoscopic scale is now known well. To clarify fundamental properties of flux pinning in iron based superconductors, we studied trapped fluxoids in Fe(Te, Se) thin film on CaF2 single crystalline substrate by use of scanning SQUID microscope. From the image of fluxoids, we estimate magnetic penetration depth and its homogeneity in the film. Influence of ferromagnetic materials will also be discussed.