Internal dynamics of long Josephson junction oscillators

Collective Josephson Vortex Dynamics in Long Josephson Junction Stacks

We investigate the collective phase dynamics in conventional long Josephson junction (LJJ) stacks and in layered superconductors, exhibiting intrinsic LJJ behaviors. Using a theoretical model which accounts for both the magnetic induction effect and the breakdown of local charge neutrality (i.e., charging effect), we show that the collective motion of Josephson vortices, including the dispersio...

On the Chaotic Flux Dynamics in a Long Josephson Junction

Flux dynamics in an annular long Josephson junction is studied. Three main topics are covered. The first is chaotic flux dynamics and its prediction via Melnikov integrals. It turns out that DC current bias cannot induce chaotic flux dynamics, while AC current bias can. The existence of a common root to the Melnikov integrals is a necessary condition for the existence of chaotic flux dynamics. ...

Microwave phase locking of Josephson-junction fluxon oscillators.

Dynamics of an underdamped Josephson-junction ladder.

We show analytically that the dynamical equations for an underdamped ladder of coupled small Josephson junctions can be approximately reduced to the discrete sine-Gordon equation. As numerical confirmation, we solve the coupled Josephson equations for such a ladder in a magnetic field. We obtain discrete-sine-Gordon-like IV characteristics, including a flux flow and a “whirling” regime at low a...

q-deformed dynamics and Josephson junction

We define a generalized rate equation for an observable in quantum mechanics, that involves a parameter q and whose limit q → 1 gives the standard Heisenberg equation. The generalized rate equation is used to study dynamics of current biased Josephson junction. It is observed that this toy model incorporates diffraction like effects in the critical current. Physical interpretation for q is prov...