Christopher Mizzi1,Fedor Balakirev1,Ivan Nekrashevich1,Maxime Leroux2,Masashi Miura3,Jens Haenisch4,Boris Maiorov1
Los Alamos National Laboratory1,Toulouse National High Magnetic Field Laboratory2,Seikei University3,Karlsruhe Institute of Technology4
Christopher Mizzi1,Fedor Balakirev1,Ivan Nekrashevich1,Maxime Leroux2,Masashi Miura3,Jens Haenisch4,Boris Maiorov1
Los Alamos National Laboratory1,Toulouse National High Magnetic Field Laboratory2,Seikei University3,Karlsruhe Institute of Technology4
A detailed understanding of vortex pinning and dynamics is imperative for technological applications of type II superconductors. In addition, it is of fundamental interest to explore vortex solids at elevated fields only accessible in pulsed magnets. One particularly powerful approach to probe vortex physics is through nonlinear electrical transport measurements. However, such characterization in high-temperature superconductors requires high magnetic fields owing to the large critical fields of these materials. Pulsed-field magnets are often used to access the magnetic fields (H) necessary to study high-temperature superconductors, but their short pulse durations (~50 ms) present technical complications for nonlinear current measurements and their large dH/dt (~1000 T/s) values raise questions about the vortex dynamics regime. In this talk, we use the recently developed non-destructive, nonlinear electrical transport capabilities in pulsed fields [1] to explore critical current and critical fields in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub> thin films with different, artificial pinning centers, and demonstrate the latest advances in this technique. We also explore the influence of the irreversibility line on critical currents at low temperatures and in fields up to 60 T.<br/><br/>[1] M. Leroux, F.F. Balakirev, M. Miura, K. Agatsuma, L. Civale, and B. Maiorov, <i>Phys. Rev. Appl.</i> <b>11</b>, 054005 (2019).