Localized Mode Oscillations of Clustered Impurities Excited by a Soliton in the Toda Lattice

抄録

The collision of a soliton with a cluster of mass impurities is studied by computer simulation. The mass ratio dependence of the energy of the localized mode is investigated form the clusters of 2∼5 impurities. The amplitude of the incident soliton is taken A=2 (force f_n=A \sech²(κn−\sqrtAt)). All frequencies of the oscillation modes that are dominantly excited fall in the range ω=2.1∼2.3, which is just above the cutoff frequency (ω_c=2.0). The saturation of the energy of the localized mode is observed at the considerably small cluster size. The property of the localized modes is also discussed theoretically in harmonic limit.