Localized self-trapping in the two-dimensional discrete molecular lattice with the interaction between Frenkel excitons and phonons

We investigate the interactions of lattice phonons with Frenkelexciton, which has a small radius in a two-dimensional discretemolecular lattice, by the virtue of the quasi-discretenessapproximation and the method of multiple-scale, and obtain that theself-trapping can also appear in the two-dimensional discrete molecularlattice with harmonic and nonlinear potential. The excitons' effecton the molecular lattice does not distort it but onlycauses it to localize which enables it to react again through phononcoupling to trap the energy and prevent its dispersion.