Anomalous Temperature Dependence of the Superfluid Density Caused by Dirty-to-Clean Crossover in FeSe${}_{0.4}$Te${}_{0.6}$ Single Crystals

Abstract

We report microwave surface impedances of FeSe${}_{0.4}$Te${}_{0.6}$ single crystals measured at 12, 19, and 44 GHz. The penetration depth exhibits a power law behavior, $\delta {\lambda }_L={\lambda }_L(T)-{\lambda }_L(0)\propto C{T}^n$ with an exponent $n\simeq 2$, which is considered to result from impurity scattering. This behavior is consistent with $s\pm$-wave pairing symmetry. The temperature dependence of the superfluid density largely deviates from the behavior expected in the BCS theory. We believe that this deviation is caused by the crossover from the dirty regime near $T_c$ to the clean regime at low temperatures, which is supported by the rapid increase of the quasiparticle scattering time obtained from the microwave conductivity. We also believe that the previously published data of the superfluid density can be interpreted in this scenario.

4 pages, 4 figures

References in corpus (14)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• High-temperature superconductivity in iron-based materials
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and superconductivity
• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• Reply to Comment on "Unconventional s-wave superconductivity in Fe(Se,Te)"
• Bulk Superconductivity at 14 K in Single Crystals of Fe1+yTexSe1-x
• Microwave Penetration Depth and Quasiparticle Conductivity in PrFeAsO_1-y Single Crystals : Evidence for a Full-Gap Superconductor
• Evidence for nodal superconductivity in LaFePO
• Microwave Surface-Impedance Measurements of the Magnetic Penetration Depth in Single Crystal Ba1-xKxFe2As2 Superconductors: Evidence for a Disorder-Dependent Superfluid Density
• Unconventional London penetration depth in Ba(Fe0.93Co0.07)2As2 single crystals
• Superfluid density and penetration depth in Fe-pnictides
• Thermodynamic phase diagram of Fe(Se${}_{0.5}$Te${}_{0.5}$) single crystals up to 28 Tesla
• Microwave Surface Impedance Measurements of LiFeAs Single Crystals
• Precision Microwave Electrodynamic Measurements of K- and Co-doped BaFe${}_2$As${}_2$

Cited by in corpus (20)

• Comprehensive Eliashberg analysis of microwave conductivity and penetration depth of K-, Co-, and P-substituted BaFe2As2
• FeTe${}_{0.55}$Se${}_{0.45}$: a multiband superconductor in the clean and dirty limit
• Superconductivity in monolayer FeSe enhanced by quantum geometry
• 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
• Exceptional Suppression of Flux-Flow Resistivity in FeSe${}_{0.4}$Te${}_{0.6}$ by Back-Flow from Excess Fe Atoms and Se/Te Substitutions
• Electrodynamic response of Ba(Fe1-xRhx)2As2 across the s+- to s++ order parameter transition
• Effect of Co Impurities on Superconductivity of FeSe0.4Te0.6 single crystals
• Superconducting Symmetry Studied from Impurity Effects in Single-Crystal Fe1-yMySe0.3Te0.7 (M = Co, Ni, Zn)
• Unusual microwave response and bulk conductivity of very thin fese0.3te0.7 films as a function of temperature
• Relationships between Superconductivity and Nematicity in FeSe${}_{1-x}$Te${}_x$ ($x=0-0.5$) Films Studied by Complex Conductivity Measurements
• Thermal conductivity and annealing effects in the iron-based superconductor FeSe${}_{0.3}$Te${}_{0.7}$
• Possible nodal superconducting gap in Fe${}_{1+y}$(Te${}_{1-x}$Se${}_x$) single crystals from ultra-low temperature penetration depth measurements
• Picosecond Trajectory of Two-dimensional Vortex Motion in FeSe${}_{0.5}$Te${}_{0.5}$ Visualized by Terahertz Second Harmonic Generation
• Contrast of LiFeAs with isostructural, isoelectronic, and non-superconducting MgFeGe
• On the determination of the quasiparticle scattering rate in unconventional superconductors by microwave surface impedance
• Superconducting Gap and Symmetry in FeSe_1-x_Te_x_ Studied by Specific Heat in Magnetic Fields
• Low-temperature-compatible tunneling-current-assisted scanning microwave microscope utilizing a rigid coaxial resonator
• Reply to "Comment on \emph{"Precision global measurements of London penetration depth in Fe(Te${}_{0.58}$Se${}_{0.42}$)"}"
• Studies of superconductivity of Fe chalcogenides in films grown by PLD technique
• Superconducting Stiffness and Coherence Length of FeSe${}_{0.5}$Te${}_{0.5}$ Measured in Zero-Applied Field