Investigation of flux turbulence in iron-based superconductors

Critical current density and vortex dynamics in pristine and proton-irradiated Ba0.6K0.4Fe2As2

“…temperatures [42,46]. Similar limitations are indicated also in IBSs, where an upper temperature limit for the Meissner hole is suggested in magneto-optical images [10,47]. However, the Meissner hole will never be the origin of the dip in the present system, since it should suppress the value of S(H) around H 0 ∼ .…”

Turbulent Structure and Characterization of ‘11’-type Iron-based Superconductors by Magneto-optical Imaging

“…Fluid-like vortices and anti-vortices with sheer velocity parallel to their interface should induce Kelvin-Helmholtz instability, perturbing the border like turbulence on liquid surfaces. Such perturbed, meandering vortex-antivortex interface is formerly reported in YBa 2 Cu 3 O 7-δ [5], MgB 2 [6], and IBSs [7,8]. From a microscopic perspective, vortices at the interface are bent to form loops with diameters larger than the minimum diameter determined by the equilibrium between pinning force and line tension.…”

“…1(c), (d)) taken along red dashed lines in Figs. 1(a) and (b) display characteristic induction steps (black arrows) induced by local excess current, or Meissner current [7,8]. In contrast to the MH in (Ba 0.67 Rb 0.33 )Fe 2 As 2 , MH in Fe(Te 0.6 Se 0.4 ) appears to be more inhomogeneous, and partly exhibit branch-like penetration (rectangle area in Fig.…”

“…Such branch-like penetration pattern could be attributed to the rugged edge from which vortex initially enter the crystal. Inverse Biot-Savart conversions [7] yield Figs. 1(e) and (f) mapping the in-plane current density for Figs.…”