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 Frenkel exciton, which has a small radius in a two-dimensional discrete molecular lattice, by the virtue of the quasi-discreteness approximation and the method of multiple-scale, and obtain that the self-trapping can also appear in the two-dimensional discrete molecular lattice with harmonic and nonlinear potential. The excitons' effect on the molecular lattice does not distort it but only causes it to localize which enables it to react again through phonon coupling to trap the energy and prevent its dispersion.