Vortex Pinning in Thin Superconducting Films and Strips

Principal Investigator: Andreas Glatz, Ph.D., Department of Physics.

In this project, we study the pinning behavior of thin superconducting films or strips. When applying a magnetic field to a superconductor it can enter in the form of discrete vortices that dissipate energy when they start moving under an applied electric current due to the Lorentz force. However, defects in the superconductor material can offset this effect by 'pinning' vortices, preventing their motion.

In superconducting films, artificial pinning arrays of localized defects can be nanofabricated and represent therefore an ideal testbed to study different mechanisms of pinning, while at the same time being technologically very important systems. Another way of restricting the motion of vortices is by changing the geometry of the sample to, e.g., narrow strips.

Here we study both, nano-patterned films and strips, using large-scale time-dependent Ginzburg-Landau numerical simulations running on GPUs. These simulations allowed to predict optimal pinning arrays for largest critical current or describe a way to use magnetoresistance measurements to analyze the vortex structure in narrow strips. Many simulations were done on Gaea at NIU. Others at ALCF at Argonne National Laboratory.

Prospective user?

Request an account.

Simulated vortex rows in YBCO submicron bridge. Shown is the superconducting order parameter amplitude as surface and density plot (from G.P. Papari, A. Glatz, F. Carillo, D. Stornaiuolo, D. Massarotti, V. Rouco, L. Longobardi, F. Beltram, V.M. Vinokur, and F. Tafuri, Geometrical vortex lattice pinning and melting in YBaCuO submicron bridges, Sci. Rep. 6, 38677 2016).
Simulated order parameter amplitude (top) and super-current magnitude (bottom) in patterned sample. Experimental results were reproduced in simulations (from I. A. Sadovskyy, Y. L. Wang, Z.-L. Xiao, W.-K. Kwok, and A. Glatz, Effect of hexagonal patterned arrays and defect geometry on the critical current of superconducting films, Phys. Rev. B 95, 075303 2017).

Prospective user?

Request an account.

Back to top