Exceptional Suppression of Flux-Flow Resistivity in FeSe${}_{0.4}$Te${}_{0.6}$ by Back-Flow from Excess Fe Atoms and Se/Te Substitutions

Abstract

We measured the microwave surface impedance of FeSe${}_{0.4}$Te${}_{0.6}$ single crystals with- and without external magnetic fields. The superfluid density exhibited a quadratic temperature dependence, indicating a strong pair-breaking effect. The flux-flow resistivity behaved as ${\rho }_f(B\ll B_{c2})/{\rho }_n=\alpha B/B_{c2}$. The observed $\alpha$ value of $\approx 0.66$ was considerably smaller than that of other Fe-based materials ($\alpha \ge 1$) and was attributed to a back-flow of superfluids remarkable in disordered superconductors. This is the first-time observation of the back-flow phenomenon caused by an origin other than the vortex pinning in multiple-band systems.

7 pages, 5 figures, and 1 table

References in corpus (8)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Density Functional Study of Excess Fe in Fe${}_{1+x}$Te: Magnetism and Doping
• Evidence for dominant Pauli paramagnetic effect in the upper critical fields of a FeTe0.6Se0.4 superconductor
• Evidence for a cos(4φ) Modulation of the Superconducting Energy Gap of Optimally Doped FeTe_{0.6}Se_{0.4} Single Crystals Using Laser Angle-Resolved Photoemission Spectroscopy
• Large, Homogeneous, and Isotropic Critical Current Density in Oxygen-Annealed Fe1+yTe0.6Se0.4 Single Crystal
• Dissociation Transition of a Composite Lattice of Magnetic Vortices in the Flux-Flow Regime of Two-Band Superconductors
• Investigation of the Superconducting Gap Structure in SrFe${}_2$(As${}_{0.7}$P${}_{0.3}$)${}_2$ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis
• Upper critical field, penetration depth, and depinning frequency of the novel high-temperature superconductor LaFeAsO${}_{0.9}$F${}_{0.1}$ studied by microwave surface impedance

Cited by in corpus (4)

• Soft Factor Subtraction and Transverse Momentum Dependent Parton Distributions on Lattice
• Vortex motion and flux-flow resistivity in dirty multiband superconductors
• Impact of the superconductors properties on the measurement sensitivity of resonant-based axion detectors
• Relationship between critical current and flux-flow resistivity in the mixed state of Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$