Probability Distribution of the Residence Times in a Periodically
Fluctuating Metastable System
R.N. Mantegna and B. Spagnolo
Istituto Nazionale di Fisica della Materia, Unità di Palermo
and
Dipartimento di Energetica ed Applicazioni di Fisica,
Università di Palermo,
Viale delle Scienze, I-90128, Palermo, Italia
We investigate experimentally and numerically the probability distribution of the residence times in a periodically fluctuating metastable system. The experiments are performed in a physical metastable system which is the series of a biasing resistor with a tunnel diode in parallel to a capacitor [1]. The numerical simulations are performed in an overdamped model system with a time dependent potential [2]. We investigate both the regime in which the system is deterministically overall-stable and overal-unstable. An overall-stable system is a system with a time dependent generalized potential well which has a finite barrier at any time , while an overall-unstable system is a system with a time dependent generalized potential well which has no barrier for a (usually short) time interval within each period of the modulating signal.
In both the stable and unstable regimes, the experimental and the
numerically determined P(T) is multi-peaked with an exponentially
decaying envelop. We note that the shape of the nth peak in the
P(T) is well fitted by a Gaussian function with standard deviation
independent of n. The same behavior has been experimentally
observed in the experiments of stochastic resonance performed in the
strong-forcing limit [3]. We study the dependence of
on the noise intensity in experiments and simulations.