Premium
Spatial breathing of the exciton distribution in ZnSe quantum wells
Author(s) -
Dal Don B.,
Zhao Hui,
Schwartz G.,
Kalt H.
Publication year - 2004
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200304128
Subject(s) - exciton , coherence (philosophical gambling strategy) , scattering , picosecond , excitation , physics , phonon , population , biexciton , monte carlo method , quantum well , atomic physics , condensed matter physics , computational physics , laser , optics , quantum mechanics , statistics , demography , mathematics , sociology
We measured the transport dynamics of excitons in ZnSe quantum wells with help of a time‐resolved nanophotoluminescence setup. Right after picosecond excitation, the excitons move out of the laser spot, but then they reverse the direction of propagation, and finally spread out again. We attribute this “spatial breathing” of the exciton population to acoustic phonon emission, which is a predominantly backward scattering event. This permits us to detect the first inelastic scattering event after the fast excitation generation, causing the end of the coherent transport regime. Using this method, we can determine simultaneously the coherence time and length of excitons in an 8nm well to 29 ps and 800 nm, respectively. We can reproduce the results with help of a Monte‐Carlo simulation of the exciton dynamics in the well. The obtained values for coherence length and time are consistent with other, independent experiments. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)