Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 57: Poster IIa

HL 57.30: Poster

Dienstag, 8. März 2005, 16:30–19:00, Poster TU E

Theory of Acoustic Phonons in Semiconductor Nanostructures: Continuum versus Microscopic Description — •Milana Michaljowa, Frank Grosse, and Roland Zimmermann — Institut für Physik der Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany

Acoustic phonons (AP) play the dominant role in dephasing of optical excitations in nanostructures at low temperatures [1]. A detailed knowledge about the AP spectrum in these low dimensional nanostructures is therefore essential for a quantitative description. Based on ab initio calculations phonon spectra for realistic quantum dot structures are calculated within the continuum elasticity theory and compared to atomistic simulations employing a valence-force-field model [2]. For a few simple geometries we compare the results with analytic expressions. We consider isotropic, cubic (zincblende), and hexagonal (wurtzite) crystal structures. Our theory is therefore applicable to a large group of compound semiconductors. Special focus is given to the InAs/GaAs and InGaN/GaN quantum dot systems.

[1] E. Muljarov and R. Zimmermann accepted Phys. Rev. Lett. 93 (2004). [2] F. Grosse and J. Neugebauer Phys. Rev. B 63, 085207 (2001).