title: Complex dynamics in unidirectionally coupled overdamped bistable systems subject to a time-periodic external signal.
abstract: Recently, we have studied the emergence of oscillatory behavior in overdamped undriven nonlinear dynamic systems subject to carefully crafted coupling schemes and operating conditions [V. In, Phys. Rev. E 68, 045102(R) (2003).] The theoretical ideas have been validated in an experimental setup of N = 3 coupled ferromagnetic cores subject to a dc external magnetic "target" signal; the oscillations (corresponding to the periodic switching of each core between its stable steady states of magnetization) are triggered when the coupling constant crosses a threshold value, with the oscillation frequency exhibiting a characteristic scaling behavior with the "separation" of the coupling constant from its threshold value, as well as with the external signal amplitude. Here, we consider the system response to a time-periodic signal. We demonstrate experimentally that, depending on the signal amplitude and frequency, the response can be either synchronized to the signal frequency or to one-third this frequency. These phenomena afford unique techniques for time-periodic signal detection and characterization for a large class of sensors.
authors.affiliation: Space and Naval Warfare Systems Center, Code 2363, 53560 Hull Street, San Diego, California 92152-5001, USA. visarath@spawar.navy.mil
authors.forename: Visarath
authors.initials: V
authors.lastname: In
authors.forename: Adi R
authors.initials: AR
authors.lastname: Bulsara
authors.forename: Antonio
authors.initials: A
authors.lastname: Palacios
authors.forename: Patrick
authors.initials: P
authors.lastname: Longhini
authors.forename: Andy
authors.initials: A
authors.lastname: Kho