Transverse phase locking in fully frustrated Josephson junction arrays: A different type of fractional giant steps

VERONICA I. MARCONI; ALEJANDRO B. KOLTON; DANIEL DOMINGUEZ; NIELS GRO?NBECH-JENSEN

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

The American Physical Society

Año: 2003 vol. 68 p. 10452101 - 10452113

0163-1829

We study, analytically and numerically, phase locking of driven vortex lattices in fully frustrated Josephsonjunction arrays at zero temperature. We consider the case when an ac current is applied perpendicular to a dccurrent. We observe phase locking, steps in the current-voltage characteristics, with a dependence on externalac-drive amplitude and frequency qualitatively different from the Shapiro steps, observed when the ac and dccurrents are applied in parallel. Further, the critical current increases with increasing transverse ac-driveamplitude, while it decreases for longitudinal ac drive. The critical current and the phase-locked current stepwidth increase quadratically with !small" amplitudes of the ac drive. For larger amplitudes of the transverse acsignal, we find windows where the critical current is hysteretic, and windows where phase locking is suppresseddue to dynamical instabilities. We characterize the dynamical states around the phase-locking interferencecondition in the current-voltage curve with voltage noise, Lyapunov exponents, and Poincare´ sections. Wefind that zero-temperature phase-locking behavior in large fully frustrated arrays is well described by aneffective four-plaquette model.