Role of Interstitial Pinning in the Dynamical Phases of Vortices in Superconducting Films

TL;DR

This study investigates how interstitial pinning influences vortex behavior in superconducting films with a Kagomé pinning network, revealing anisotropic transport properties and complex vortex phases through numerical simulations.

Contribution

It introduces a detailed analysis of vortex dynamics considering anisotropic interstitial pinning in a Kagomé lattice, highlighting new vortex phases and resistance peaks.

Findings

Observation of anisotropic differential resistance peaks

Identification of vortex phases depending on pinning and forces

Complex vortex behavior linked to interstitial vacancies

Abstract

We analyze the vortex dynamics in superconducting thin films with a periodic array of pinning centers. In particular, we study the effect of anisotropy for a Kagom\'e pinning network when longitudinal and transverse transport currents are applied. By solving the equations of motion for the vortex array numerically at zero temperature we find different phases for the vortex dynamics depending on the pinning and driving force. An unusual sequence of peaks along and perpendicular to the main hexagonal lattice axes is observed for the differential resistance reflecting the anisotropy of the transport properties and the complex behavior of the vortex system. This behavior may be understood in terms of interstitial pinning vacancies, which create channels of vortices with different pinning strength.