Research output: Contribution to journal › Article › peer-review
Damping of Rabi oscillations in intensity-dependent photon echoes from exciton complexes in a CdTe/(Cd,Mg)Te single quantum well. / Poltavtsev, S. V.; Reichelt, M.; Akimov, I. A.; Karczewski, G.; Wiater, M.; Wojtowicz, T.; Yakovlev, D. R.; Meier, T.; Bayer, M.
In: Physical Review B-Condensed Matter, Vol. 96, No. 7, 075306, 18.08.2017.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Damping of Rabi oscillations in intensity-dependent photon echoes from exciton complexes in a CdTe/(Cd,Mg)Te single quantum well
AU - Poltavtsev, S. V.
AU - Reichelt, M.
AU - Akimov, I. A.
AU - Karczewski, G.
AU - Wiater, M.
AU - Wojtowicz, T.
AU - Yakovlev, D. R.
AU - Meier, T.
AU - Bayer, M.
N1 - Funding Information: We acknowledge financial support of the Deutsche Forschungsgemeinschaft through the Collaborative Research Centre TRR 142 (Project No. A02) and the International Collaborative Research Centre 160, the latter of which is also supported by the Russian Foundation of Basic Research (Project No. N 15-52-12016 NNIO _ a ). M.B. acknowledges partial financial support from the Russian Ministry of Science and Education (Contract No. 14.Z50.31.0021). The research in Poland was partially supported by the National Science Centre (Poland) through Grants No. DEC-2012/06/A/ST3/00247 and No. DEC-2014/14/M/ST3/00484, as well as by the Foundation for Polish Science through the International Research Agenda Program cofinanced by the European Union within Smart Growth Operational Program. Publisher Copyright: © 2017 American Physical Society. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2017/8/18
Y1 - 2017/8/18
N2 - We study Rabi oscillations detected in the coherent optical response from various exciton complexes in a 20-nm-thick CdTe/(Cd,Mg)Te quantum well using time-resolved photon echoes. In order to evaluate the role of exciton localization and inhomogeneous broadening we use selective excitation with spectrally narrow ps pulses. We demonstrate that the transient profile of the photon echo from the localized trion (X-) and the donor-bound exciton (D0X) transitions strongly depends on the strength of the first pulse. It acquires a non-Gaussian shape and experiences significant advancement for pulse areas larger than π due to non-negligible inhomogeneity-induced dephasing of the oscillators during the optical excitation. Next, we observe that an increase of the area of either the first (excitation) or the second (rephasing) pulse leads to a significant damping of the photon echo signal, which is strongest for the neutral excitons and less pronounced for the donor-bound exciton complex (D0X). The measurements are analyzed using a theoretical model based on the optical Bloch equations which accounts for the inhomogeneity of optical transitions in order to reproduce the complex shape of the photon echo transients. In addition, the spreading of Rabi frequencies within the ensemble due to the spatial variation of the intensity of the focused Gaussian beams and excitation-induced dephasing are incorporated in our model, which is able to explain the fading and damping of Rabi oscillations. By analyzing the results of the simulation for X- and D0X complexes we are able to establish a correlation between the degree of localization and the transition dipole moments determined as μ(X-)=73 D and μ(D0X)=58 D.
AB - We study Rabi oscillations detected in the coherent optical response from various exciton complexes in a 20-nm-thick CdTe/(Cd,Mg)Te quantum well using time-resolved photon echoes. In order to evaluate the role of exciton localization and inhomogeneous broadening we use selective excitation with spectrally narrow ps pulses. We demonstrate that the transient profile of the photon echo from the localized trion (X-) and the donor-bound exciton (D0X) transitions strongly depends on the strength of the first pulse. It acquires a non-Gaussian shape and experiences significant advancement for pulse areas larger than π due to non-negligible inhomogeneity-induced dephasing of the oscillators during the optical excitation. Next, we observe that an increase of the area of either the first (excitation) or the second (rephasing) pulse leads to a significant damping of the photon echo signal, which is strongest for the neutral excitons and less pronounced for the donor-bound exciton complex (D0X). The measurements are analyzed using a theoretical model based on the optical Bloch equations which accounts for the inhomogeneity of optical transitions in order to reproduce the complex shape of the photon echo transients. In addition, the spreading of Rabi frequencies within the ensemble due to the spatial variation of the intensity of the focused Gaussian beams and excitation-induced dephasing are incorporated in our model, which is able to explain the fading and damping of Rabi oscillations. By analyzing the results of the simulation for X- and D0X complexes we are able to establish a correlation between the degree of localization and the transition dipole moments determined as μ(X-)=73 D and μ(D0X)=58 D.
UR - http://www.scopus.com/inward/record.url?scp=85028993278&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.96.075306
DO - 10.1103/PhysRevB.96.075306
M3 - Article
AN - SCOPUS:85028993278
VL - 96
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 7
M1 - 075306
ER -
ID: 40725310