2018/07/31 by Roland Willa, Mariano Marziali Bermúdez, G. Pasquini +1
Engineering · Materials Science · Physics and Astronomy · #Condensed matter physics #Critical current #Flux pinning #High-temperature superconductivity #Hysteresis #Magnetic and transport properties of perovskites and related materials #Materials science #Mechanics #Penetration depth #Physics #Physics of Superconductivity and Magnetism #Pinning force #Quantum mechanics #Superconducting Materials and Applications #Superconductivity #Thermal #Type-II superconductor #Vortex #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.98.184520
published as Phys. Rev. B 98, 184520 (2018) · 7 pages, 5 figures
openalex publication_date 2018/11/30 · arxiv created 2019/04/11 · arxiv updated 2019/04/12 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
In type-II superconductors, the macroscopic response of vortex matter to an external perturbation depends on the local interaction of flux lines with the pinning landscape (pinscape). The (Campbell) penetration depth \ensuremathλC of an ac field perturbation is often associated with a phenomenological pinning curvature. However, this basic approach is unable to capture thermal hysteresis effects observed in a variety of superconductors. The recently developed framework of strong-pinning theory has established a quantitative relationship between the microscopic pinscape and macroscopic observables. Specifically, it identifies history-dependent vortex arrangements as the primary source for thermal hysteresis in the Campbell response. In this work, we show that this interpretation is well-suited to capture the experimental results of the clean superconductor NbSe2, as observed through Campbell response (linear ac susceptibility) and small-angle neutron scattering measurements. Furthermore, we exploit the hysteretic Campbell response upon thermal cycling to extract the temperature dependence of microscopic pinning parameters from bulk measurements, specifically the pinning force and pinning length. This spectroscopic tool may stimulate further pinscape characterization in other superconducting systems.