Normal state resistivity of Ba1−x K x Fe2As2: evidence for multiband strong-coupling behavior

Golubov, Alexandre Avraamovitch; Dolgov, O. V.; Boris, A. V.; Charnukha, Aliaksei; Sun, Dunlu; Lin, C. T.; Shevchun, A. F.; Korobenko, Alexey V.; Trunin, M. R.; Zverev, V. N.

doi:10.1134/s0021364011160041

Cited by 32 publications

(44 citation statements)

References 18 publications

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“…Broad crossover in the temperature-dependent resistivity is observed in in-plane transport in single crystals of BaK122 at doping close to optimal [38], similar to pure stoichiometric KFe 2 As 2 (K122) [39][40][41][42][43]. Explanation of the crossover was suggested as arising from multi-band effects [38], with contribution of two conductivity channels, as found in optical studies [44] with nearly temperature-independent and strongly temperature dependent resistivities, respectively.…”

Section: Introductionmentioning

confidence: 79%

“…5. The origin of the feature was discussed in terms of multiband character of conductivity in which one of the bands has strongly temperature dependent contribution, while the other has nearly temperature independent conductivity [38], as contribution from phonon-assisted scattering between two Fermi-surface sheets [45] and as a feature associated with pseudogap, as suggested by its correlation with the maximum of the interplane transport ρ c (T ) in underdoped compositions [24,25,30]. The position of the crossover does not change with doping, and since the Fermi surface topology reveals quite significant changes [61], the explanation of the maximum in term of special features of band structure [38,45] is very unlikely.…”

Section: Resultsmentioning

confidence: 99%

“…Explanation of the crossover was suggested as arising from multi-band effects [38], with contribution of two conductivity channels, as found in optical studies [44] with nearly temperature-independent and strongly temperature dependent resistivities, respectively. The maximum in ρ a (T ) of BaK122 was discussed by Gasparov et al [45] as arising from phonon-assisted scattering between two Fermi-surface sheets.…”

Section: Introductionmentioning

confidence: 99%

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Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)Fe
Liu
¹
,
Tanatar
²
,
Straszheim
³

et al. 2014
Phys. Rev. B
64
15
72
2
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Large high-quality single crystals of hole-doped iron-based superconductor (Ba1-xKx)Fe2As2 were grown over a broad composition range 0.22 <= x <= 1 by inverted temperature gradient method. We found that high soaking temperature, fast cooling rate, and an adjusted temperature window of the growth are necessary to obtain single crystals of heavily K-doped crystals (0.65 <= x <= 0.92) with narrow compositional distributions as revealed by sharp superconducting transitions in magnetization measurements and close to 100% superconducting volume fraction. The crystals were extensively characterized by x-ray and compositional analysis, revealing monotonic evolution of the c-axis crystal lattice parameter with K substitution. Quantitative measurements of the temperature-dependent in-plane resistivity rho(T) found doping-independent, constant within error bars, resistivity at room temperature, rho(300 K), in sharp contrast with the significant doping dependence in electron and isovalent substituted BaFe2As2 based compositions. The shape of the temperature-dependent resistivity, rho(T), shows systematic dopingevolution, being close to T-2 in overdoped and revealing significant contribution of the T-linear component at optimum doping. The slope of the upper critical field, d H-c2/dT, scales linearly with T-c for both H parallel to c, H-c2,(c), and H parallel to ab, H-c2,H-ab. The anisotropy of the upper critical field. equivalent to Hc(2,ab)/H-c2,H-c determined near zero-field T-c increases from similar to 2 to 4-5 with increasing K doping level from optimal x similar to 0.4 to strongly overdoped x = 1. Large high-quality single crystals of hole-doped iron-based superconductor (Ba 1−x K x )Fe 2 As 2 were grown over a broad composition range 0.22 x 1 by inverted temperature gradient method. We found that high soaking temperature, fast cooling rate, and an adjusted temperature window of the growth are necessary to obtain single crystals of heavily K-doped crystals (0.65 x 0.92) with narrow compositional distributions as revealed by sharp superconducting transitions in magnetization measurements and close to 100% superconducting volume fraction. The crystals were extensively characterized by x-ray and compositional analysis, revealing monotonic evolution of the c-axis crystal lattice parameter with K substitution. Quantitative measurements of the temperature-dependent in-plane resistivity ρ(T ) found doping-independent, constant within error bars, resistivity at room temperature, ρ(300 K), in sharp contrast with the significant doping dependence in electron and isovalent substituted BaFe 2 As 2 based compositions. The shape of the temperature-dependent resistivity, ρ(T ), shows systematic doping-evolution, being close to T 2 in overdoped and revealing significant contribution of the T -linear component at optimum doping. The slope of the upper critical field, dH c2 /dT , scales linearly with T c for both H c, H c2,c , and H ab, H c2,ab . The anisotropy of the upper critical field γ ≡ H c2,ab /H c2,c determined near z...

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Section: Introductionmentioning

confidence: 79%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)Fe
Liu
¹
,
Tanatar
²
,
Straszheim
³

et al. 2014
Phys. Rev. B
64
15
72
2
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“…The maximum of the spectra is sf = 144 cm −1 , which determines the natural energy scale [28]. This spectrum gives a rather good description of thermodynamical [58] and optical [59,60] properties in the SC as well as normal states [61]. Moreover, we will use all temperatures and energies, expressed below, in the units of inverse cm (i.e., cm −1 In the strong-coupling approach, as opposed to the weakcoupling limit, the gap functions are complex and frequency dependentφ α =φ α (ω).…”

Section: The Eliashberg Approachmentioning

confidence: 99%

Quasiparticle interference in multiband superconductors with strong coupling

et al. 2017

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We develop a theory of the quasiparticle interference (QPI) in multiband superconductors based on the strong-coupling Eliashberg approach within the Born approximation. In the framework of this theory, we study dependencies of the QPI response function in the multiband superconductors with the nodeless s-wave superconductive order parameter. We pay special attention to the difference in the quasiparticle scattering between the bands having the same and opposite signs of the order parameter. We show that at the momentum values close to the momentum transfer between two bands, the energy dependence of the quasiparticle interference response function has three singularities. Two of these correspond to the values of the gap functions and the third one depends on both the gaps and the transfer momentum. We argue that only the singularity near the smallest band gap may be used as a universal tool to distinguish between the s ++ and s ± order parameters. The robustness of the sign of the response function peak near the smaller gap value, irrespective of the change in parameters, in both the symmetry cases is a promising feature that can be harnessed experimentally.

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“…Optical conductivity as measured by THz spectrometry provides and estimate of τ e ≈ 4τ h , 12 and reflectivity measurements also suggest the presence of two distinct scattering rates with a large disparity between them. [13][14][15] Theoretical analysis of the normal state resistivity ρ in the two-band model for Ba 1−x K x Fe 2 As 2 shows that the experimental temperature dependence ρ(T ) can be reproduced only if one assumes order of magnitude larger scattering in the hole band 16 . Finally, quantum oscillation experiments on P-doped systems indicate that the electron pockets have a longer mean free path [17][18][19] .…”

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confidence: 99%

Anisotropic quasiparticle lifetimes in Fe-based superconductors

et al. 2011

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We study the dynamical quasiparticle scattering by spin and charge fluctuations in Fe-based pnictides within a 5-orbital model with onsite interactions. The leading contribution to the scattering rate is calculated from the second-order diagrams with the polarization operator calculated in the random phase approximation. We find one-particle scattering rates which are highly anisotropic on each Fermi surface sheet due to the momentum dependence of the spin susceptibility and the multi-orbital composition of each Fermi pocket. This fact combined with the anisotropy of the effective mass and Fermi velocity, produce disparity between electrons and holes in conductivity, Hall coefficient, and Raman initial slope in qualitative agreement with experimental data.

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Normal state resistivity of Ba1−x K x Fe2As2: evidence for multiband strong-coupling behavior

Cited by 32 publications

References 18 publications

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)Fe
Liu
¹
,
Tanatar
²
,
Straszheim
³

et al. 2014
Phys. Rev. B
64
15
72
2
View full text Add to dashboard Cite

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)Fe
Liu
¹
,
Tanatar
²
,
Straszheim
³

et al. 2014
Phys. Rev. B
64
15
72
2
View full text Add to dashboard Cite

Quasiparticle interference in multiband superconductors with strong coupling

Anisotropic quasiparticle lifetimes in Fe-based superconductors

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Normal state resistivity of Ba1−x K x Fe2As2: evidence for multiband strong-coupling behavior

Cited by 32 publications

References 18 publications

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)FeLiu1, Tanatar2, Straszheim3 et al. 2014Phys. Rev. B6415722View full textAdd to dashboardCite

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)FeLiu1, Tanatar2, Straszheim3 et al. 2014Phys. Rev. B6415722View full textAdd to dashboardCite

Quasiparticle interference in multiband superconductors with strong coupling

Anisotropic quasiparticle lifetimes in Fe-based superconductors

Contact Info

Product

Resources

About

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)Fe
Liu
¹
,
Tanatar
²
,
Straszheim
³

et al. 2014
Phys. Rev. B
64
15
72
2
View full text Add to dashboard Cite

Comprehensive scenario for single-crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba1−xKx)Fe
Liu
¹
,
Tanatar
²
,
Straszheim
³

et al. 2014
Phys. Rev. B
64
15
72
2
View full text Add to dashboard Cite