Rezumat
CZU 538.9+539.189.1
This paper studies the dynamics of an electron in a three-center nanocluster that is embedded in the non-dissipative matrix and is influenced by a periodic electric field. The proposed model uses the Holstein's Hamiltonian, in which the additional addends taking into account the action with the external electric field and the effect of non-dissipative matrix are included. With that, the three-center nanocluster is considered together with the ligand environment of its centers and the interaction of an electron with local vibrations in the ligand environment is taken into account. The obtained system of differential equations is solved numerically for different values of model parameters (internal and external). The various regimes of the electron density distribution in the nanotrimer are identified. The approach presented here focuses attention on the account of the influence of the low-frequency electric field. Both the temporal dynamics of the electronic subsystem of trimeric nanocluster and the energy distribution between the intracluster vibrational modes of its vibrational subsystems are analyzed. In addition, the role of an external mode of the matrix interacting with the intracluster modes is revealed. It is found that depending on the certain combination of the internal and external parameters of the given model either an accumulation (localization) of the electron density at any of the nanotrimer centers or a delocalization of the electron density between two or even three of its centers can occur. In turn, the electron density distribution in the trimer affects its dipole moment, and thereby determines the polarization properties of such composite material.
Keywords: three-center nanocluster, regimes of electron density distribution, non-dissipative matrix, periodic electric field, electron-vibrational interaction.