Doping-evolution of the superconducting gap in single crystals of (Ca_1−xLa_x)₁₀(Pt₃As₈)(Fe₂As₂)₅superconductor from London penetration depth measurements

Abstract

The doping-evolution of the superconducting gap structure in iron-based superconductor (Ca −x min c ). Both the decrease of the exponent and the increase of the absolute value of Δλ in the underdoped regime are similar to the observations in other charge-doped iron-based superconductors, such as doped BaFe 2 As 2 and NaFeAs, suggesting a universal behavior in iron-based superconductors.

Optical properties of optimally doped single-crystal Ca8.5La1.5(Pt3As8)(Seo1, Choi2, Kimura3 et al. 2017Phys. Rev. B116120View full textAdd to dashboardCite

“…And recent angle resolved photoemission spectroscopy (ARPES) experiment further suggested that this difference between two compounds could be developed by the number of the band-edge singularities 9 . In order to study this subtle relation between the electronic structure and superconductivity in these materials, various experiments have already been performed: such as transport 10 , pressure effect 11 , ARPES 7 , magnetic force microscope (MFM) 12 , upper critical field (H c2 ) 13 , nuclear magnetic resonance (NMR) 14 , and penetration depth λ(T ) 15 measurements, etc. However, the IR spectroscopy experiment has not yet been carried out with these compounds.…”

Weak pinning and vortex bundles in anisotropic Ca$_{10}$(Pt$_4$As$_8$)[(Fe$_{1-x}$Pt$_x$)$_2$As$_2$]$_5$ single crystals

“…The uncertainty of the λ extrapolation from 4 K to 0 K is as small as few percent, and thus negligible compared to the main source of the uncertainty. 11 The 10-4-8 phase Ca 10 (Pt 4−δ As 8 )[(Fe 0.97 Pt 0.03 ) 2 As 2 ] 5 with δ ≈ 0.246 and T c = 26.5 K shows H c2 (0) values of around 90 T for H//c and 92 T for H//ab. 14 The upper critical field anisotropy thus changes from ≈ 7 close to T c to ≈ 1 at low temperatures.…”

“…Superconductivity in this system occurs under applied pressure 8 or with chemical doping. [9][10][11] The two different types of intermediate layers (n = 3 and n = 4) affect significantly the physical properties of these highly anisotropic compounds. 5,12 For example, the optimally doped Ca 10 (Pt 3 As 8 )[(Fe 1−x Pt x ) 2 As 2 ] 5 has a superconducting transition temperature (T c ) around 10 K and an upper critical field of H c c2 (0) ∼ 20 T. 13 The upper critical field anisotropy (γ = H ab c2 /H c c2 ) decreases from 10 close to T c to 1.5 at low temperatures.…”

Optical properties of the optimally doped Ca$_{8.5}$La$_{1.5}$(Pt$_3$As$_8$)(Fe$_{2}$As$_{2}$)$_5$ single crystal

“…And recent angle resolved photoemission spectroscopy (ARPES) experiment further suggested that this difference between two compounds could be developed by the number of the band-edge singularities 9 . In order to study this subtle re-lation between the electronic structure and superconductivity in these materials, various experiments have already been performed: such as transport 10 , pressure effect 11 , ARPES 7 , magnetic force microscope (MFM) 12 , upper critical field (H c2 ) 13 , nuclear magnetic resonance (NMR) 14 , and penetration depth λ(T ) 15 measurements, etc. However, the IR spectroscopy experiment has not yet been carried out with these compounds.…”