Modulational instability of zone boundary mode and band edge modes in nonlinear diatomic lattices.
We analyze the modulational instability of the zone boundary mode (ZBM) and the band edge modes (BEMs) in a one-dimensional nonlinear diatomic lattice and obtain rigorous results. Some numerical calculations of modulational instability in these modes are presented. These results indicate that the modulational instability of the BEMs leads to excitation of the discrete breathers (DBs) in the band gap, while that of the ZBM leads to excitation of the DBs above the phonon band.
Doi
Yusuke
Y
Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. doi@ams.eng.osaka-u.ac.jp
Nakatani
Akihiro
A
Yoshimura
Kazuyuki
K