2015/12/31 by Roland Willa, R. Willa, V. B. Geshkenbeǐn +2 · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Critical current #Flux pinning #Lambda #London penetration depth #Magnetic properties of thin films #Penetration depth #Physics #Physics of Superconductivity and Magnetism #Pinning force #Quantum mechanics #Superconductivity #Thermodynamics #Type-II superconductor #Vortex #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.93.064515
16 pages, 11 figures
openalex publication_date 2016/02/23 · arxiv created 2016/03/22 · arxiv updated 2016/03/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Type-II superconductors owe their magnetic and transport properties to vortex pinning, the immobilization of flux quanta through material inhomogeneities or defects. Characterizing the potential energy landscape for vortices, the pinning landscape (or short, pinscape), is of great technological importance. Aside from measurement of the critical current density jc and of creep rates S, the ac magnetic response provides valuable information on the pinscape which is different from that obtained through jc or S, with the Campbell penetration depth \ensuremathλC defining a characteristic quantity well accessible in an experiment. Here, we derive a microscopic expression for the Campbell penetration depth \ensuremathλC using strong-pinning theory. Our results explain the dependence of \ensuremathλC on the state preparation of the vortex system and the appearance of hysteretic response. Analyzing different pinning models, metallic or insulating inclusions, as well as \ensuremathδTc and \ensuremathδ\ensuremathℓ pinning, we discuss the behavior of the Campbell length for different vortex-state preparations within the phenomenological H\text\ensuremath-T phase diagram and compare our results with recent experiments.