Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 36: Quantenpunkte und -dr
ähte: Optische Eigenschaften I

HL 36.2: Vortrag

Donnerstag, 11. März 2004, 10:30–10:45, H17

Dephasing in Quantum Dots: Quadratic Coupling to Acoustic Phonons — •Egor Muljarov^1,2, Frank Grosse¹, and Roland Zimmermann¹ — ¹Institut für Physik der Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany — ²General Physics Institute RAS, Vavilova 38, Moscow 119991, Russia

A microscopic theory of optical transitions in quantum dots with carrier-phonon interaction is developed. Virtual transitions into higher confined states with acoustic phonon assistance add a quadratic phonon coupling to the standard linear one, thus extending the independent Boson model. Summing infinitely many diagrams in the cumulant, an exact solution for the interband polarization is found. Its full time dependence and the absorption lineshape of the quantum dot are calculated. A temperature-dependent broadening of the zero-phonon line is obtained and compared with available experimental data.