Classifying Superconductivity in an Infinite-Layer Nickelate Nd0.8Sr0.2NiO2

Recently Li et al (2019 Nature 572 624) discovered a new type of oxide superconductor Nd0.8Sr0.2NiO2 with Tc = 14 K. To classify superconductivity in this infinite-layer nickelate experimental upper critical field, Bc2(T), and the self-field critical current densities, Jc(sf,T), reported by Li et al (2019 Nature 572 624), are analysed in assumption of s-, d-, and p-wave pairing symmetries and single- and multiple-band superconductivity. Based on deduced the ground-state superconducting energy gap, Δ(0), the London penetration depth, λ(0), the relative jump in electronic specific heat at Tc, ΔC/C, and the ratio of 2Δ(0)/kBTc, we conclude that Nd0.8Sr0.2NiO2 is type-II high-κ weak-coupled single-band s-wave superconductor.