https://doi.org/10.1140/epjb/e2007-00249-5
Acoustic phonon transmission spectra in piezoelectric AlN/GaN Fibonacci phononic crystals
1
Departamento de Física, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN, Brazil
2
Departamento de Física, Universidade Federal do Ceará, Campus do Pici, 60455-760 Fortaleza-CE, Brazil
Corresponding author: a eudenilson@dfte.ufrn.br
Received:
2
May
2007
Revised:
14
August
2007
Published online:
22
September
2007
We study the acoustic-phonon transmission spectra in periodic and quasiperiodic (Fibonacci type) superlattices made up from the III-V nitride materials AlN and GaN. The phonon dynamics is described by a coupled elastic and electromagnetic equations within the static field approximation model, stressing the importance of the piezoelectric polarization field in a strained condition. We use a transfer-matrix treatment to simplify the algebra, which would be otherwise quite complicated, allowing a neat analytical expressions for the phonon transmission coefficients. Numerical results, for the normal incidence case, show a strike self-similar pattern for both hexagonal (class 6 mm) and cubic symmetries crystalizations of the nitrides.
PACS: 63.20.Dj – Phonon states and bands, normal modes, and phonon dispersion / 63.22.+m – Phonons or vibrational states in low-dimensional structures and nanoscale materials / 77.65.-j – Piezoelectricity and electromechanical effects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007
