title: Periodic phase synchronization in coupled chaotic oscillators.
abstract: We investigate the characteristics of temporal phase locking states observed in the route to phase synchronization. It is found that before phase synchronization there is a periodic phase synchronization state characterized by periodic appearance of temporal phase-locking state and that the state leads to local negativeness in one of the vanishing Lyapunov exponents. By taking a statistical measure, we present the evidences of the phenomenon in unidirectionally and mutually coupled chaotic oscillators, respectively. And it is qualitatively discussed that the phenomenon is described by a nonuniform oscillator model in the presence of noise.
authors.affiliation: National Creative Research Initiative Center for Controlling Optical Chaos, Pai-Chai University, Daejeon 302-735, Korea.
authors.forename: Won-Ho
authors.initials: WH
authors.lastname: Kye
authors.forename: Dae-Sic
authors.initials: DS
authors.lastname: Lee
authors.forename: Sunghwan
authors.initials: S
authors.lastname: Rim
authors.forename: Chil-Min
authors.initials: CM
authors.lastname: Kim
authors.forename: Young-Jai
authors.initials: YJ
authors.lastname: Park