Created-by-current states in long Josephson junctions

TL;DR

This paper investigates the stability and bifurcation phenomena of fluxon states in long Josephson junctions with inhomogeneity and variable width, revealing new stable regions and bifurcation points influenced by junction parameters.

Contribution

It introduces the concept of created-by-current states in inhomogeneous long Josephson junctions and analyzes their stability and bifurcations based on junction geometry and inhomogeneity.

Findings

Existence of magnetic field regions where fluxon states are stable only with non-zero current.

Appearance of noncentral fluxon states with increasing junction length.

Identification of new bifurcation points related to inhomogeneity width and current amplitude.

Abstract

Critical curves "critical current - external magnetic field" of long Josephson junctions with inhomogeneity and variable width are studied. We demonstrate the existence of the regions of magnetic field where some fluxon states are stable only, if the external current through the junction is different from zero. Position and size of such regions depend on length of the junction, its geometry, parameters of inhomogeneity and form of the junction. The noncentral (left and right) pure fluxon states are appeared in the inhomogeneous Josephson junction with increase in the junction length. We demonstrate new bifurcation points with change in width of the inhomogeneity and amplitude of the Josephson current through the inhomogeneity.