Evidence for multiple gaps in specific heat of LiFeAs crystals

Abstract

The zero-field specific heat of LiFeAs was measured on several single crystals selected from a bulk sample. A sharp Delta Cp/Tc anomaly of approximately 20 mJ/(mole x K^2) was observed. The value appears to be between those of SmFeAs(O0.9F0.1) and (Ba0.6K0.4)Fe2As2, but bears no clear correlation with their Sommerfeld coefficients. The electronic specific heat below Tc further reveals a two-gap structure with the narrower one only on the order of 0.7 meV. While the results are in rough agreement with the Hc1(T) previously reported on both LiFeAs and (Ba0.6K0.4)Fe2As2, they are different from the published specific-heat data of a (Ba0.6K0.4)Fe2As2 single crystal.

arXiv comment19 pages, 5 figures

References in corpus (23)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11
• Phenomenological two-gap model for the specific heat of MgB_2
• The BCS-like gap in superconductor SmFeAsO_0.85F_0.15
• Low temperature specific heat of the hole-doped Ba_{0.6}K_{0.4}Fe_2As_2 single crystals and electron-doped SmFeAsO_{0.9}F_{0.1} samples
• Fully Gapped Superconducting State Based on a High Normal State Quasiparticle Density of States in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Evidence for Two Gaps and Breakdown of the Uemura Plot in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Two-gap superconductivity in Ba_1-xK_xFe_2As_2: A complementary study of the magnetic penetration depth by \muSR and ARPES
• Multiple phase transitions in single-crystalline Na${}_{1-\delta }$FeAs
• Specific heat measurements of the gap structure of the organic superconductors kappa-(ET)_2Cu[N(CN)_2]Br and kappa-(ET)_2Cu(NCS)_2
• Superconductivity: Exotic Commonalities in Phase and Mode
• Point contact Andreev reflection spectroscopy of superconducting energy gaps in 122-type family of iron pnictides
• Point-contact Andreev-reflection spectroscopy in ReFeAsO_{1-x}F_x (Re = La, Sm): Possible evidence for two nodeless gaps
• Electronic specific heat and low energy quasiparticle excitations in superconducting state of $L{a}_{2-x}S{r}_{x}Cu{O}_4$ single crystals
• Thermal properties of SmFeAs(O1-xFx) as probe of the interplay between electrons and phonons
• Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states
• Lower Critical Field, Anisotropy, and Two-Gap Features of LiFeAs
• Coexistence of Supercondcutivity and Magnetism in LaFeAs(O0.94F0.06) Probed by Muon Spin Relaxation

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• Microwave Surface Impedance Measurements of the Electronic State and Dissipation of Magnetic Vortices in Superconducting Iron-Based LiFeAs Single Crystals
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• Anomalous hysteresis as an evidence for a magnetic field-induced chiral superconducting state in LiFeAs
• Small and nearly isotropic hole-like Fermi surfaces in LiFeAs detected through de Haas van Alphen-effect
• Investigation of LiFeAs by means of "Break-junction" Technique
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• Probing the Order Parameter of Superconducting LiFeAs using Pb/LiFeAs and Au/LiFeAs Point-Contact Spectroscopy
• Coexistence of Clean- and Dirty-limit Superconductivity in LiFeAs
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• Multiband superconductivity and a deep gap minimum from the specific heat in KCa${}_2$(Fe${}_{1-x}$Ni${}_x$)${}_4$As${}_4$F${}_2$ ($x$ = 0, 0.05, 0.13)