Zero-field superfluid density in ad-wave superconductor evaluated from muon-spin-rotation experiments in the vortex state

Abstract

We report on measurements of the in-plane magnetic penetration λ ab in the optimally doped cuprate superconductor (BiPb)2(SrLa)2CuO 6+δ (OP Bi2201) by means of muon-spin rotation (µSR). We show that in unconventional d−wave superconductors (like OP Bi2201), µSR experiments conducted in various magnetic fields allow to evaluate the zero-field magnetic penetration depth λ0, which relates to the zero-field superfluid density in terms of ρs ∝ λ Muon-spin-rotation (µSR) measurements in the mixed state of type-II superconductors provide valuable information on the superconducting properties. An important advantage of this method is that the muons probe the bulk of the material, and the results are not complicated by surface imperfections. The quantitative parameters extracted from µSR experiments depend, however, on the details of the model applied to reconstruct the internal magnetic field distribution in the superconductor in the mixed state. So far, field distributions measured by means of µSR were analyzed within the framework of analytical models based on London and GinzburgLandau (GL) theories, which can be applied, in general, to conventional superconductors with a single isotropic energy gap.

Spin Polaron-Bipolaron Scenario of Three Gap-Like Energy Scales in Superconducting Cuprates

“…Similar conclusions have been drawn from infrared ellipsometry measurements of the c-axis conductivity of underdoped RBa 2 Cu 3 O 7−δ (R = Y, Nd, and La) single crystals [31]. A separate study of the in-plane magnetic penetration depth λ ab in optimally doped (BiPb) 2 (SrLa) 2 CuO 6+δ which was performed by means of muon-spin rotation (µSR) gives rise to similar conclusions [32]. The measurement results are inconsistent with a simple model of a d-wave order parameter and a uniform quasiparticle weight around the Fermi surface.…”

Suppression of the antinodal coherence of superconducting(Bi,Pb)2(Sr,La)Khasanov1, Kondo2, Bendele3 et al. 2010Phys. Rev. BSelf Cite112120View full textAdd to dashboardCite

“…As shown in Ref. 7 the relation ef f ͑H , T͒Ӎ ab ͑T͒ is still valid in the limit of low magnetic fields H Շ 10 −3 H c2 ͑0͒.…”

“…The decrease in sc for OP35K and OD29K is a consequence of both, the nonlinear and the nonlocal response of the superconductor containing nodes in the energy gap to the increasing magnetic field. 7 The solid lines for OD29K and OP35K correspond to fits of the relation sc ͑H͒ / sc ͑H =0͒ =1−K · ͱ H to sc ͑H͒ which takes into account the nonlinear correction to s for a superconductor with a d-wave energy gap. 11 The analysis of sc ͑H͒ for UD23K reveals, however, that only at very low fields ͑Շ30 mT͒ sc follows the tendency observed for OP and OD Bi2201 samples.…”

“…1 by following the procedure described in Ref. 7. It includes, first, the reconstruction of the effective penetration depth ef f ͑H , T͒ from sc ͑H , T͒ by using the relation sc ͑H , T͒ = 4.83 13 Here H c2 is the upper critical field with the zero-temperature values 0 H c2 ͑0͒Ӎ60 T, Ӎ50 T, and Ӎ45 T for UD23K, OP35K, and OD29K, respectively, 14 and with the T dependence following the Werthamer-Helfand-Hohenberg ͑WHH͒ prediction.…”

Single-gap versus two-gap scenario: Specific heat and thermodynamic critical field of the noncentrosymmetric superconductor BeAu

“…Measurements of temperature dependences of thermodynamic quantities such as the superfluid density ρ s , the electronic specific heat C e , and the thermodynamic critical field B c are among the primary ways used to test pairing mechanisms of new superconductors [1][2][3][4][5][6]. In particular, such experiments allow us (i) to distinguish between the single-band and multiband scenarios [7][8][9][10][11][12][13][14], (ii) to determine the superconducting gap structure [15][16][17][18][19][20][21][22][23][24][25][26], (iii) to calculate the temperature evolution(s) of the superconducting energy gaps [27][28][29][30][31][32][33], etc. Obviously, the parameters obtained from the analysis of various thermodynamic quantities need to be consistent with each other.…”