Acoustic phonon sideband dynamics during polaron formation in a single quantum dot
Abstract
When an electron–hole pair is optically excited in a semiconductor quantum dot, the host crystal lattice adapts to the presence of the generated charge distribution. Therefore, the coupled exciton–phonon system has to establish a new equilibrium, which is reached in the form of a quasiparticle called a polaron. Especially, when the exciton is abruptly generated on a timescale faster than the typical lattice dynamics, the lattice cannot follow adiabatically. Consequently, rich dynamics on the picosecond timescale of the coupled system is expected. In this study, we combine simulations and measurements of the ultrafast, coherent, nonlinear optical response, obtained by four-wave mixing (FWM) spectroscopy, to resolve the formation of this polaron. By detecting and investigating the phonon sidebands in the FWM spectra for varying pulse delays and different temperatures, we have access to the influence of phonon emission and absorption processes, which finally result in the emission of an acoustic wave packet.
Citation
Wigger , D , Karakhanyan , V , Schneider , C , Kamp , M , Höfling , S , Machnikowski , P , Kuhn , T & Kasprzak , J 2020 , ' Acoustic phonon sideband dynamics during polaron formation in a single quantum dot ' , Optics Letters , vol. 45 , no. 4 , pp. 919-922 . https://doi.org/10.1364/OL.385602
Publication
Optics Letters
Status
Peer reviewed
ISSN
0146-9592Type
Journal article
Description
TK, DW & PM acknowledge support form the Polish National Agency for Academic Exchange under the International Academic Partnerships program, the Würzburg group by the State of Bavaria and C.S by the DFG (project Schn1376-5.1).Collections
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