Static and dynamic properties of 0, pi, and 0-pi ferromagnetic tunnel Josephson Junctions

TL;DR

This study investigates the static and dynamic behaviors of 0, pi, and 0-pi ferromagnetic Josephson junctions, revealing complex resonant phenomena and magnetic field effects through detailed experimental analysis.

Contribution

It provides new experimental insights into the dynamical properties and magnetic field responses of 0, pi, and 0-pi SIFS Josephson junctions, including the observation of half-integer zero field steps.

Findings

Resonant steps observed in current-voltage characteristics.

Critical current varies with in-plane magnetic field components.

Half-integer zero field step demonstrated in 0-pi junctions.

Abstract

We present experimental studies of static and dynamic properties of 0, pi and 0-pi 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-pi Josephson junction is demonstrated by measuring the critical current as a function of two components (B_x, B_y) of an in-plane magnetic field. The experimental observation of a half-integer zero field step in 0-pi SIFS junctions is presented.