Microscopic Parameters from High-Resolution Specific Heat Measurements on Overdoped BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ Single Crystals

Abstract

We investigate the electronic specific heat of overdoped BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ single crystals in the superconducting state using high-resolution nanocalorimetry. From the measurements, we extract the doping dependence of the condensation energy, superconducting gap $\Delta$, and related microscopic parameters. We find that the anomalous scaling of the specific heat jump $\Delta C\propto T_{\mathrm{c}}^3$, found in many iron-based superconductors, in this system originates from a $T_{\mathrm{c}}$-dependent ratio $\Delta /k_{\mathrm{B}}{T}_{\mathrm{c}}$ in combination with a doping-dependent density of states $N({\epsilon }_{\mathrm{F}})$. A clear enhancement is seen in the effective mass $m^{\ast }$ as the composition approaches the value that has been associated with a quantum critical point at optimum doping. However, a simultaneous increase in the superconducting carrier concentration $n_{\mathrm{s}}$ maintains the superfluid density, yielding an apparent penetration depth $\lambda$ that decreases with increasing $T_{\mathrm{c}}$ without sharp divergence at the quantum critical point. Uemura scaling indicates that $T_{\mathrm{c}}$ is governed by the Fermi temperature $T_{\mathrm{F}}$ for this multi-band system.

5 pages, 3 figures

References in corpus (9)

• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
• Superconductivity up to 30 K in the vicinity of quantum critical point in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Condensation, excitation, pairing, and superfluid density in high-$T_c$ superconductors: magnetic resonance mode as a roton analogue and a possible spin-mediated pairing
• Different response of the crystal structure to isoelectronic doping in BaFe2[As(1-x)P(x)]2 and [Ba(1-x)Sr(x)]Fe2As2
• Enhanced Fermi surface nesting in superconducting BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ revealed by de Haas-van Alphen effect
• Membrane-based nanocalorimeter for high-resolution measurements of low-temperature specific heat
• Absolute accuracy in membrane-based ac nanocalorimetry
• Superconducting gap evolution in overdoped BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ single crystals through nanocalorimetry

Cited by in corpus (9)

• Comprehensive Eliashberg analysis of microwave conductivity and penetration depth of K-, Co-, and P-substituted BaFe2As2
• Spontaneously broken translational symmetry at edges of high-temperature superconductors: thermodynamics in magnetic field
• Spin excitations in optimally P-doped BaFe2(As0.7P0.3)2superconductor
• In-plane anisotropy of transport coefficients in the electronic nematic states: Universal origin of the nematicity in Fe-based superconductors
• Fluctuations and pairing in Fe-based superconductors: Light scattering experiments
• Spontaneous symmetry-breaking at surfaces of $d$-wave superconductors: influence of geometry and surface ruggedness
• Anomalous sharp peak in the London penetration depth induced by the nodeless-to-nodal superconducting transition in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Superconducting gap and nematic resonance at the quantum critical point observed by Raman scattering in $\mathrm{BaF}{\mathrm{e}}_2({\mathrm{As}}_{1-x}{\mathrm{P}}_x{)}_2$
• Mass enhancement in multiple bands approaching optimal doping in a high-temperature superconductor