Static and dynamic properties of 0, π, and 0−π ferromagnetic Josephson tunnel junctions

We present experimental studies of static and dynamic properties of 0, π, and 0−π superconductor-insulator-ferromagnet-superconductor (SIFS) Josephson junctions of small and intermediate length. In the underdamped limit, these junctions exhibit a rich dynamical behavior such as resonant steps on the current-voltage characteristics. Varying the experimental conditions, zero-field steps, Fiske steps, and Shapiro steps are observed with a high resolution. A strong signature of the 0−π Josephson junction is demonstrated by measuring the critical current as a function of two components (Bx and By) of an in-plane magnetic field. The experimental observation of a half-integer zero-field step in 0−π SIFS junctions is presented