Full polar optical phonon states and dispersive spectra of a wurtzite GaN/AlN rectangular quantum wire

Abstract

Within the framework of the dielectric continuum model and Loudon's uniaxial crystal model, the full polar optical phonon modes including the quasi-confined (QC) modes, the propagating (PR) modes, the half-space (HS) modes, and the interface optical (IO) modes in a quasi-one-dimensional (Q1D) wurtzite rectangular quantum wire (QWR) structure are deduced and analyzed. The analytical phonon states, their dispersion equations and polar polarization eigenvectors are derived. Numerical calculation of dispersive spectra for these modes is performed on a wurtzite GaN/AlN rectangular QWR. The behavior of the QC mode reducing to the IO mode is observed clearly in the dispersive curves of these modes, which reveals that the present theories of phonon modes are self-consistency and correct for the description of phonon modes in wurtzite Q1D rectangular NW. These observations and results reveal that the confined dimensionality and cross-section shape influence greatly the dispersive properties of phonon modes in wurtzite quantum confined systems.