Josephson Junction Revisited

An Extraordinary Josephson Junction

The combination of symmetry breaking effects, such as those occurring in magnets and superconductors, with topological order may result in remarkable new physics. Recent theoretical studies suggest that, in certain superconductors, exotic quasiparticle excitations can emerge that behave like Majorana fermions, chargeneutral quasiparticles that are their own antiparticles. In Physical Review Let...

Duality in Josephson Junction Arrays

Various properties of mesoscopic two-dimensional Josephson junction arrays are reviewed. Particular attention is paid to structure of the topological excitations, charges and vortices, which are shown to be dual to each other. This duality persists in the presence of external magnetic fields and offset charges, which influence vortices and charges in an equivalent way. A double-layer junction a...

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...

Phases of Josephson junction ladders.

We study a Josephson junction ladder in a magnetic field in the absence of charging effects via a transfer matrix formalism. The eigenvalues of the transfer matrix are found numerically, giving a determination of the different phases of the ladder. The spatial periodicity of the ground state exhibits a devil’s staircase as a function of the magnetic flux filling factor f . If the transverse Jos...

Josephson tunnel junction microwave attenuator