 
Summary: Stability of dynamic coherent states in intrinsic Josephsonjunction stacks near internal
cavity resonance
A. E. Koshelev
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
Received 25 August 2010; published 16 November 2010
Stacks of intrinsic Josephson junctions in the resistive state can by efficiently synchronized by the internal
cavity mode resonantly excited by the Josephson oscillations. We study the stability of dynamic coherent states
near the resonance with respect to small perturbations. Three states are considered: the homogeneous and
alternatingkink states in zero magnetic field and the homogeneous state in the magnetic field near the value
corresponding to half flux quantum per junction. We found two possible instabilities related to the shortscale
and longscale perturbations. The homogeneous state in modulated junction is typically unstable with respect
to the shortscale alternating phase deformations unless the Josephson current is completely suppressed in one
half of the stack. The kink state is stable with respect to such deformations and homogeneous state in the
magnetic field is only stable within a certain range of frequencies and fields. Stability with respect to the
longrange deformations is controlled by resonance excitations of fast modes at finite wave vectors and
typically leads to unstable range of the wave vectors. This range shrinks with approaching the resonance and
increasing the inplane dissipation. As a consequence, in finiteheight stacks the stability frequency range near
the resonance increases with decreasing the height.
DOI: 10.1103/PhysRevB.82.174512 PACS number s : 74.50. r, 85.25.Cp, 74.81.Fa
I. INTRODUCTION
