Supersolitons in layered Josephson structures

It is demonstrated that in a system of parallel-coupled long Josephson junctions forming a layered superconducting structure there are nonlinear excitations of coupled fluxon arrays in the form of dynamical ‘‘supersolitons’’ [A. V. Ustinov, Phys. Lett. A 136, 155 (1989)]. The supersolitons in the system may be of two types, dynamical kinks and envelope solitons. The former ones are described by the elliptic-lattice equation which is transformed into the sine-lattice equation in the case of the dense fluxon arrays or the modified Boussinesq equation in the continuum limit. The latter solitons are oscillating ones and are described by the nonlinear Schrödinger equation in the discrete carrier case. These solitons may be important in transport properties of the flux flow in layered superconductors or high-${\mathit{T}}_{\mathit{c}}$ superconductors with twins under external magnetic fields. The stability of the nonlinear excitations is briefly discussed.