Anisotropic type-I superconductivity and anomalous superfluid density in OsB 2

Abstract

We present a microscopic study of superconductivity in OsB2 , and discuss the origin and characteristic length scales of the superconducting state. From first-principles we show that OsB2 is characterized by three different Fermi sheets, and we prove that this fermiology complies with recent quantum-oscillation experiments. Using the found microscopic properties, and experimental data from the literature, we employ Ginzburg-Landau relations to reveal that OsB2 is a distinctly type-I superconductor with very low Ginzburg-Landau parameter kappa - a rare property among compound materials. We show that the found coherence length and penetration depth corroborate the measured thermodynamic critical field. Moreover, our calculation of the superconducting gap structure using anisotropic Eliashberg theory and ab initio calculated electron-phonon interaction as input reveals a single but anisotropic gap. The calculated gap spectrum is shown to give an excellent account for the unconventional behavior of the superfluid density of OsB2 measured in experiments as a function of temperature. This reveals that gap anisotropy can explain such behavior, observed in several compounds, which was previously attributed solely to a two-gap nature of superconductivity.

References in corpus (7)

• Superfluid density and specific heat within self-consistent scheme for two-band superconductor
• The Suprafroth (Superconducting Froth)
• Ginzburg-Landau theory for multiband superconductors: microscopic derivation
• Experimental evidence for a two-band superconducting state of NbSe2 single crystals
• Multi-gap superconductivity and Shubnikov-de Haas oscillations in single crystals of the layered boride OsB_2
• Exceptional type-I superconductivity of the layered silver oxide Ag${}_5$Pb${}_2$O${}_6$
• Multiband character of $\beta$-FeSe: Angular dependence of the magnetoresistance and upper critical field

Cited by in corpus (10)

• Evolution of multi-gap superconductivity in the atomically thin limit: Strain-enhanced three-gap superconductivity in monolayer MgB${}_2$
• Advanced first-principles theory of superconductivity including both lattice vibrations and spin fluctuations: The case of FeB${}_4$
• muSR and Magnetometry Study of the Type-I Superconductor BeAu
• Niobium in clean limit: an intrinsic type-I superconductor
• Evidence for Unconventional Superconductivity and Nontrivial Topology in PdTe
• Superconducting density of states and bandstructure at the surface of the candidate topological superconductor Au2Pb
• The field theory of a superconductor with repulsion
• Multiband effects on the upper critical field angular dependence of 122-family iron pnictide superconductors
• Influence of pressure on properties of multi-gap type-I superconductor BeAu
• Ginzburg-Landau surface energy of multiband superconductors: Derivation and application to selected systems