Interface and longitudinal optical phonon modes in cylindrical quantum dots

We report the interface and longitudinal-optical phonon modes in cylindrical quantum dots using the dielectric-continuum model. We also investigate the effect of the dot surrounding materials on both the top-surface optical (TSO) and the side-surface optical (SSO) phonon modes. We observe that the symmetric and antisymmetric TSO modes are cylinder-radius dependent for the heterostructure system. On the other hand, in the free-standing dots, only the symmetric TSO branch shows a significant dependence with the cylinder radius, while the SSO modes are cylinder-radius independent for the large radius in both cases.