Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Exciton dephasing via phonon interactions in InAs quantum dots: dependence on quantum confinement

Borri, Paola, Langbein, Wolfgang Werner, Woggon, U., Stavarache, V., Reuter, D. and Wieck, A. D. 2005. Exciton dephasing via phonon interactions in InAs quantum dots: dependence on quantum confinement. Physical Review B: Condensed Matter and Materials Physics 71 (11) , 115328. 10.1103/PhysRevB.71.115328

[img]
Preview
PDF
Download (89kB) | Preview

Abstract

We report systematic measurements of the dephasing of the excitonic ground-state transition in a series of InGaAs?GaAs quantum dots having different quantum confinement potentials. Using a highly sensitive four-wave mixing technique, we measure the polarization decay in the temperature range from 5 to 120 K on nine samples having the energy distance from the dot ground-state transition to the wetting layer continuum (confinement energy) tuned from 332 to 69 meV by thermal annealing. The width and the weight of the zero-phonon line in the homogeneous line shape are inferred from the measured polarization decay and are discussed within the framework of recent theoretical models of the exciton-acoustic phonon interaction in quantum dots. The weight of the zero-phonon line is found to decrease with increasing lattice temperature and confinement energy, consistently with theoretical predictions by the independent Boson model. The temperature-dependent width of the zero-phonon line is well reproduced by a thermally activated behavior having two constant activation energies of 6 and 28 meV, independent of confinement energy. Only the coefficient to the 6-meV activation energy shows a systematic increase with increasing confinement energy. These findings rule out that the process of one-phonon absorption from the excitonic ground state into higher energy states is the underlying dephasing mechanism.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Biosciences
Physics and Astronomy
Subjects: Q Science > QC Physics
Publisher: American Physical Society
ISSN: 1098-0121
Last Modified: 01 Jun 2019 22:14
URI: http://orca.cf.ac.uk/id/eprint/1541

Citation Data

Cited 127 times in Google Scholar. View in Google Scholar

Cited 124 times in Scopus. View in Scopus. Powered By Scopus® Data

Cited 93 times in Web of Science. View in Web of Science.

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics