Vortex Pinning in a YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ Thin Film

Vortices, and the nanoscale structures that pin them, are important both fundamentally and for the development of high temperature superconductor technologies. We use a home-built magnetic force microscope (MFM) to determine the depinning forces required to move individual vortices in a 200nm thick YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ film. Our results indicate a wide distribution of depinning forces for different vortices. A comparison between distributions at various temperatures is underway, qualitatively showing a decrease of forces with increasing temperature.