Dynamics of the Josephson Multi-Junction Systems with Junctions Characterized by Non-Sinusoidal Current - Phase Relationship

It is shown that the inclusion of junctions characterized by non-sinusoidal current - phase relationship in the systems composed of multiple Josephson junctions - results in the appearance of additional system phase states. Numerical simulations and stability considerations confirm that these phase states can be realized in practice. Moreover, spontaneous formation of the grain boundary junctions in high-T$\text{}_{c}$ superconductors with non-trivial current-phase relations due to the d-wave symmetry of the order parameter is probable. Switching between the phase states of multiple grain boundary junction systems can lead to additional 1/f noise in high-T$\text{}_{c}$ superconductors.