Speaker
Description
Nonlinear electrical transport is an indispensable tool to study disorder, dimensionality, criticality, and vortex physics for fundamental research on new types of superconductors and technological applications. Because a significant portion of many superconducting phase diagrams occurs at very high magnetic fields ($\it{H}$) only accessible by pulsed field magnets, there is a need to develop non-linear transport capabilities compatible with the stringent challenges imposed by pulsed fields. Among the many technical challenges of performing non-linear electrical transport measurements in pulsed fields, short pulse durations (~50 ms) and large d$\it{H}$/dt values (~10$^{4}$ T/s) are perhaps the most difficult. Large d$\it{H}$/dt values are especially challenging because they generate vortex motion which competes with current induced vortex motion [1]. In this talk, I will show recent developments at the National High Magnetic Field Lab’s Pulsed Field Facility which enable efficient, non-destructive, non-linear electrical transport measurements in pulsed fields. With our state-of-the-art system, we can collect, and immediately analyze, non-linear electrical transport data utilizing the entire field range (55T) accessible within a single pulse [1, 2]. I will present critical current and critical field measurements on YBa$_{2}$Cu$_3$O$_{7-x}$ thin films with different, artificial pinning centers which demonstrate our capabilities, and explore the influence of the irreversibility line on critical currents at low temperatures and in fields up to 65T. Comparisons will also be drawn between the properties of superconducting cuprate thin films and the newly discovered nickelate family of superconductors.
[1] M. Leroux, F.F. Balakirev, M. Miura, K. Agatsuma, L. Civale, and B. Maiorov, $\it{Phys. Rev. Appl.} \bf{\:11}$, 054005 ($\bf{2019}$).
[2] C.A. Mizzi, F.F. Balakirev, B. Maiorov, et al., $\it{In\:preparation}$.
Acknowledgement
This work was supported by the Los Alamos National Laboratory LDRD program, project number 20210320ER. The National High Magnetic Field Laboratory, which hosts the high magnetic field magnets, is funded by NSF Cooperative Agreements No. DMR-1157490 and No. 1164477, the State of Florida and Department of Energy.
