The effect of Vortex Core Shape in Molecular Dynamics Simulations of Abrikosov Vortices in Ratchet Modulated Superconducting Films

Molecular dynamics simulations is widely used to model vortex motion in superconducting films by treating them as point-like objects subject to their overdamped equation of motion. However, for simulations focusing on flux trapping in height modulated films, the full shape of the vortex can play a critical role. To account for the vortex shape, we begin with the Ginzburg-Landau free energy of a vortex with a Clem profile in a film with an arbitrary height modulation. By calculating the force from this free energy, the simulation is able to treat the vortex as a point-like object while applying an effective pinning force that accounts for its core shape. We apply this technique to ratchet and sinusoidal modulated films in the presence of AC and DC drive forces. We study the impacts of this technique on the resultant vortex ratchet effect, Shapiro steps, and their interplay, to determine how temperature affects vortex transport in a ratchet pinning potential landscape.