Moving discrete breathers in nonlinear lattice: Resonance and stability

• DOI: 10.1016/j.wavemoti.2007.04.004
• Publication Date: 2007-04-26T13:03:09Z
• Authors: Kazuyuki Yoshimura; Yusuke Doi
• Keywords: 0103 physical sciences; 01 natural sciences

Abstract We have studied moving discrete breathers in the Fermi–Pasta–Ulam β lattice. The moving discrete breathers are not strictly localized but have spatially extended tails. It is shown that a resonance phenomenon in the tail amplitude occurs: the tail amplitude is enhanced for some particular values of the breather frequency and these values depend on the velocity. This resonance is caused by strong excitation of a particular set of the harmonic normal modes. We analytically derive a condition for this resonance. Moreover, we analyze the linear stability of moving discrete breathers and show that the instability appears when the breather frequency is close to the resonance points.