Quantification of the flux tubes and the stability of stripe pattern in the intermediate state of a type-1 superconducting film

The intermediate state in a type-1 superconducting Pb film is studied by using the scanning Hall probe microscopy, which shows quantized flux tubes with distinct flux density. The vorticity of flux tubes are quantified using the monopole model. It is found that the vorticity of the flux tubes can be tuned by using flux expulsion process under different magnetic field and temperatures. The stability of stipe patterns at high fields is studied with new stripe patterns formed after shaking with ah ac field. No flux tube is observed even after shaking with intense ac fields. All the results suggests the stripe patterns have very close energy, which is much favorable than the flux tube state.