Project Info

Vortex Dynamics in Superconductors

Serena Eley | serenaeley@mines.edu

The current carrying capacity Jc of type-II superconductors is severely limited by dissipation from the motion of vortices, magnetic flux lines that appear inside these materials upon immersion in sufficiently high magnetic fields. To date, no superconductor has achieved a Jc higher than ~25-30% its theoretical maximum Jd and, most samples produce Jc closer to 1-2% Jd. Vortex-defect interactions are enormously important in determining superconductor properties. In fact, intentionally incorporating disorder can remarkably enhance Jc and slow creep (rate of thermally activated vortex motion). Despite considerable previous research on superconductor vortex dynamics, serious gaps exist that have relegated optimizing disorder landscapes to a process of trial-and-error. Creep rates are not predictable and no analytic expression exists that broadly captures the temperature and field dependence of creep. However, it is known that creep rates should depend on both the Ginzburg number Gi and Jc/Jd. The goal of this project is to draw correlations between Jc/Jd and creep. This will involve perusing the literature for measurements of vortex creep and superconducting parameters that determine the Gi and Jd as well as measuring vortex creep and Jc in a variety of samples using a low temperature magnetometer.

For more information:
1. Eley, S., Miura, M., Maiorov, B. & Civale, L. Universal lower limit on vortex creep in superconductors. Nat. Mater. 16, 409–413 (2017).
2. Foltyn, S. R. et al. Materials science challenges for high-temperature superconducting wire. Nature Mater. 6, 631–642 (2007).
3. Kwok, W.-K. et al. Vortices in high-performance high-temperature superconductors. Rep. Prog. Phys. 79, 116501 (2016).
4. Yeshurun, Y., Malozemoff, A. P. & Shaulov, A. Magnetic relaxation in high- temperature superconductors. Rev. Mod. Phys. 68, 911–949 (1996).
5. Blatter, G., Feigel’man, M. V., Geshkenbein, V. B., Larkin, A. I. & Vinokur, V. M. Vortices in high-temperature superconductors. Rev. Mod. Phys. 66, 1125–1388 (1994).
6. Superconducting vortices Youtube channel: https://www.youtube.com/channel/UCjdQ4Ruhxma5pkxGrFxw3CA

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