Stiffness and coherence length measurements of ultra-thin superconductor, and implications to layered superconductors

Abstract

Based on the London equation, we use a rotor-free vector potential $\mathbf{A}$, and current measurements by a SQUID, to determine the superconducting Pearl length $\Lambda$, and coherence length $\xi$, of ultra-thin, ring shaped, MoSi films, as a function of thickness $d$ and temperature $T$. We find that $\xi$ is a function of $d$ with a jump at $\xi \sim d\sim 5$nm. At base temperature the superconducting stiffness, defined by $1/{\lambda }^2=1/(\Lambda d)$, is an increasing function of $T_c$. Similar behavior, known as the Uemura plot, exist in bulk layered superconductors, but with doping as an implicit parameter. We also provide the critical exponents of $\Lambda (T)$.

7 pages, 7 figures

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Cited by in corpus (2)

• Mixed superconducting state without applied magnetic field
• Superconducting Stiffness and Coherence Length of FeSe${}_{0.5}$Te${}_{0.5}$ Measured in Zero-Applied Field