In this paper, we study the phonon transmission coefficient of a mass-spring chain including two or more electric charges by using Green’s function method within the harmonic approximation. The chain is supposed to be embedded between two simple phononic leads. To this end, the effect of Columb interaction between charges are inserted to their force constants. The results show that for the case of existence just electrical dipole in the system, the phonon transmission coefficient decreases by increasing the distance of charge positions. Moreover, the increasing the number of ions in the center chain, decreases the phonon transmission coefficient, specially, at the low and intermediate frequencies.
Silicon nanowires have attracted the attention of many researchers in recent years due to their electrical and mechanical properties and also its potential applications in many fields such as biosensors. In this study, we theoretically investigated the phonon transport through silicon nanowires in the presence of isotope impurities. Heat transfer properties of silicon nanowires in the <100> direction were studied using the non-equilibrium Green’s function method and the impurity atoms were placed in the middle part of the structure. The results of this research showed that, in the presence of isotope impurity, thermal conductivity decreases. The effect of impurity atom mass was also investigated and the results of this study also indicated that with the increase in the mass of the impurity atom, the thermal conductivity decreases more and the reason for this should be investigated in the dependence of the phonon frequency on the mass.
