Synchronization and Chaos Control Features in Arrays of Intrinsic Josephson Junctions

Synchronization properties of model systems containing large numbers of phase oscillators have many potential biophysical and other applications. Biophysical examples include networks of pacemaker cells in the heart and suprachiasmatic nucleus of the brain. In physical systems the phase dynamics of high-Tc superconducting materials continue to attract attention, since systems of intrinsic Josephson junctions form natural arrays of coupled phase oscillators. As such, they have the potential to act as systems in which various exotic synchronization effects, such as the relatively recently discovered chimera states, may be naturally observed. In this study we make a detailed exploration of the wider parameter space containing regions of chaos synchronization in the CCJJ+DC model of intrinsic Josephson junctions. Extensive regions of phase synchronization - corresponding to the Shapiro steps with zero charge density in the S-layers - are found through numerical simulation. By computing the Lyapunov exponent spectra, we see that chaos synchronization occurs only within certain sub-regions that overlap with 'uncharged' steps in the IV-characteristics. Such chaos synchronization may be useful in applications requiring more powerful, high-frequency, chaotic signals.