Quantum Breathers in a Nonlinear Lattice
Quantum Breathers in a Nonlinear Lattice
We study nonlinear phonon excitations in a one-dimensional quantum nonlinear lattice model using numerical exact diagonalization. We find that multiphonon bound states exist as eigenstates which are natural counterparts of breather solutions of classical nonlinear systems. In a translationally invariant system, these quantum breather states form particlelike bands and are …