2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/91694The spectrum of the Quantum Discrete Nonlinear Schrödinger equation on a periodic 1D lattice shows some interesting detailed band structure which may be interpreted as the quantum signature of a two-breather interaction in the classical case. We show that this fine structure can be interpreted using degenerate perturbation theory.4 pages, 4 figsQuantum PhysicsSoft Condensed MatterPattern Formation and Solitonstext