Effects of correlated noise on the excitation of robust breathers in an ac-driven, lossy sine-Gordon system

Abstract

Thermal noise and harmonic forcing have recently been shown to cooperatively excite sine–Gordon breathers robust to dissipation. Such a phenomenon has been found assuming a Gaussian noise source, delta-correlated both in time and space. In light of the potential implications of this generation technique, e.g., for the experimental observation of breathers in long Josephson junctions, it is physically motivated to investigate the effects of more realistic noise sources with finite correlation time and/or correlation length. Here, breathers are demonstrated to still emerge under this broader class of noise sources. The correlation time and the correlation length are found to offer control over the probability of observing breathers, as well on the typical timescale for their emergence. In particular, our results show that, as compared to the thermal case, the temporal and spatial correlations in the noise can lead to a larger breather-only occurrence frequency, i.e., the latter quantity behaves nonmonotonically versus both the correlation time and the correlation length. Overall, noise correlations represent a powerful tool for controlling the excitation of the elusive breather modes in view of experiments.