Josephson Junctions: Theory and Applications

This lecture covers the theoretical background and practical applications of Josephson junctions, focusing on the Josephson effects, non-linear current-phase relation, and Josephson energy. It explains the fabrication process of Josephson Tunnel Junctions, critical current, and the coupling to external fields. The lecture also discusses the AC Josephson effect, DC SQUID, qubit frequency tunability, and the energy levels of the Cooper Pair Box. It delves into the split CPB, energy levels in charge and phase basis, and the tunability of Josephson energy. The presentation concludes with a detailed analysis of the Cooper pair box, including the circuit setup, energy quantization, and the impact of gate voltage on additional Cooper pairs.