Giant Shapiro resonances in a flux driven Josephson junction necklace

Shapiro steps in Josephson Junctions

We use Ginzburg-Landau theory to describe the phase transition to the superconducting state and the current through a superconductor. Applying quantum mechanics to the Josephson junction following Feynmann’s method the Josephson relations for AC and DC current through the junctions is obtained. The resistively shunted Josephson junction and the resistively and capacitively shunted Josephson jun...

Phase locking and flux-flow resonances in Josephson oscillators driven by homogeneous microwave fields

Harmonic resonances in nonlinear Josephson junction circuits: experimental and analytical studies

This thesis presents a study of resonance dynamics in circuits of superconducting Josephson junctions. The Josephson junction is an intrinsically nonlinear device which, under certain conditions, can exhibit harmonic oscillations. This research begins with the dynamics of Josephson junctions connected in parallel with either periodic (ring geometry) or open-ended (row geometry) boundary conditi...

Screening in Josephson-junction ladders.

Both critical current and Shapiro steps in Josephson ladders are found to show effects of vortex exclusion below a critical magnetic field. Vortices are excluded even though the flux itself is not screened out. When current is injected perpendicular to the ladder edges, the critical current is unchanged from its f50 value up to a penetration field of f c1''0.12 flux quanta per plaquette. Simila...

Non-equilibrium charge and spin transport in SFS point contacts

The conventional Josephson effect may be modified by introducing spin-active scattering in the interfacelayer of the junction. Here, we discuss a Josephson junction consisting of two s-wave superconducting leads coupled over a classical spin that precesses with the Larmor frequency due to an external magnetic field. This magnetically active interface results in a time-dependent boundary conditi...