Titlebar

Export bibliographic data
Literature by the same author
plus on the publication server
plus at Google Scholar

 

Pure dephasing and phonon dynamics in GaAs- and GaN-based quantum dot structures : Interplay between material parameters and geometry

Title data

Krummheuer, B. ; Axt, Vollrath M. ; Kuhn, Tilmann ; D'Amico, I. ; Rossi, F.:
Pure dephasing and phonon dynamics in GaAs- and GaN-based quantum dot structures : Interplay between material parameters and geometry.
In: Physical Review B. Vol. 71 (2005) Issue 23 . - No. 235329, 13 Seiten.
ISSN 0163-1829
DOI: https://doi.org/10.1103/PhysRevB.71.235329

Project information

Project financing: Deutsche Forschungsgemeinschaft
European Commission within the Future and Emerging Technologies (FET) project Semiconductor-based implementation of quantum information devices.

Abstract in another language

The pure dephasing of excitons in quantum dot structures due to their interaction with acoustic phonons as well as the spatiotemporal dynamics of the created nonequilibrium phonon population is studied theoretically. The theory is applied to GaAs- as well as GaN-based heterostructures. A detailed analysis of the interplay between different material parameters, different quantum dot geometries, and different electric fields is presented. The optical polarization induced by an ultrashort laser pulse exhibits a characteristic nonexponential behavior: it decays on a pico- or subpicosecond time scale to a value that strongly depends on temperature, structure, and material parameters and is then retained until, on a typically much longer time scale, it finally decays because of electron-hole recombination or transitions to other states. We find that, in general, the remnant optical polarization is much higher in the GaAs-based structures than in the GaN-based structure mainly because of the strongly enhanced piezoelectric coupling in GaN quantum dots. The optical excitation also leads to the buildup of a phonon population consisting of a polaron part that remains localized in the region of the quantum dot and a traveling part that leaves the dot region at the speed of sound. This traveling part exhibits characteristic anisotropies reflecting both the anisotropy of the quantum dot structure and of the coupling matrix elements.

Further data

Item Type: Article in a journal
Refereed: Yes
Keywords: quantum dot; generating functions; non-linear optics; ultrafast dynamics; pure dephasing; phonons; analytical solutions; excitons; polaron formation; Non-perturbative solution; decoherence; dephasing; excitons; non-Markovian dynamics; GaN dots; GaAs dots; phonon wave packets; piezoelectric dot-phonon coupling; anisotropic phonon propagation
Institutions of the University: Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics
Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Theoretical Physics III > Chair Theoretical Physics III - Univ.-Prof. Dr. Martin Axt
Faculties
Faculties > Faculty of Mathematics, Physics und Computer Science
Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Theoretical Physics III
Result of work at the UBT: No
DDC Subjects: 500 Science > 530 Physics
Date Deposited: 23 Oct 2017 11:05
Last Modified: 23 Oct 2017 11:05
URI: https://eref.uni-bayreuth.de/id/eprint/40124