Optical-phonon modes in a double heterostructure of polar crystals

Abstract

The equation of motion for the polarization vector for a double heterostructure of polar crystals is solved exactly within the framework of the continuum model. There exist only two types of phonon modes, the interface modes and the confined bulk modes, whose eigenvectors are obtained explicitly. Dispersion relations are derived analytically for the interface modes, while the confined bulk modes are dispersionless, a fact consistent with the model. It is also found that in Raman scattering experiments the symmetric interface modes are predominantly longitudinal optical (LO) and the antisymmetric interface modes transverse optical (TO). In the central region of the Brillouin zone, ho~ever, they both split into two branches oscillating at LO and TO frequencies, respectively. Possible reinterpretation of various experiments is briefly discussed.

Properties of interface phonon spectra in complicated cylindrical nanosystem

“…The phonon spectrum is treated within the framework of the dielectric continuum model widely applied for low-dimensional crystal structures [6][7][8][9] and the results of which are in good correlation with the experimental data.…”

Optical phonon modes in a free-standing quantum wire with ring geometry

“…To derive the free phonon Hamiltonian, we need the dynamic equations of motion of the crystal lattice [15,17,25]:…”

Free Carrier Absorption in Quantum Well Structures Due to Confined and Interface Optical Phonons

“…41' l G; : 1 2 Itna(q)l' 6 ( E k + q , l * --hS2 T R w L l ) . (26) q 1'2 n , u = * The upper sign (-) refers to phonon absorption and the lower sign (+) to phonon emission.…”