Dynamic properties of asymmetric double Josephson junction stack with quasiparticle imbalance

Area of Science:

• Condensed Matter Physics
• Superconductivity
• Quantum Electronics

Background:

• Josephson junctions are fundamental components in superconducting electronics.
• Asymmetric Josephson stacks exhibit complex dynamics influenced by junction properties.
• Quasiparticle dynamics play a crucial role in the behavior of superconducting devices.

Purpose of the Study:

• To investigate the impact of quasiparticle charge imbalance on the dynamics of an asymmetric Josephson stack.
• To analyze the influence of junction switching on the effective critical currents of individual junctions.
• To understand the role of quasiparticle relaxation times in shaping current-voltage characteristics.

Main Methods:

• Analytical modeling of quasiparticle charge imbalance effects.
• Numerical simulations of Josephson junction dynamics.
• Examination of current-voltage characteristics under varying conditions.

Main Results:

• Switching the fast capacitive junction to a resistive state enhances the slow junction's critical current.
• The effect of switching the slow junction on the fast junction's critical current depends on resistance ratios and capacitance.
• Slow quasiparticle relaxation introduces additional hysteresis in current-voltage characteristics.

Conclusions:

• Quasiparticle charge imbalance significantly modifies Josephson stack dynamics.
• The interplay between junction switching and material properties dictates critical current modifications.
• Understanding quasiparticle relaxation is key to controlling hysteresis in superconducting devices.