Exploring coherence of individual excitons in InAs quantum dots embedded in natural photonic defects : influence of the excitation intensity
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The exact optical response of quantum few-level systems depends crucially on the exact choice of the incoming pulse areas. We use four-wave mixing (FWM) spectroscopy to infer the coherent response and dynamics of single InAs quantum dots (QDs) and study their pulse area dependence. By combining atomic force microscopy with FWM hyperspectral imaging, we show that the retrieved FWM signals originate from individual QDs enclosed in natural photonic defects. The optimized light-matter coupling in these defects allows us to perform our studies in a wide range of driving field amplitudes. When varying the pulse areas of the exciting laser pulses Rabi rotations of microscopic interband coherences can be resolved by the two-pulse FWM technique. We investigate these Rabi coherence rotations within two- and three-level systems, both theoretically and experimentally, and explain their damping by the coupling to acoustic phonons. To highlight the importance of the pulse area in uence, we show that the phonon-induced dephasing of QD excitons depends on the pulse intensity.
Wigger , D , Mermillod , Q , Jakubczyk , T , Fras , F , Le-Denmat , S , Reiter , D E , Höfling , S , Kamp , M , Nogues , G , Schneider , C , Kuhn , T & Kasprzak , J 2017 , ' Exploring coherence of individual excitons in InAs quantum dots embedded in natural photonic defects : influence of the excitation intensity ' Physical Review. B, Condensed matter and materials physics , vol 96 , no. 16 , 165311 . DOI: 10.1103/PhysRevB.96.165311
Physical Review. B, Condensed matter and materials physics
© 2017 American Physical Society. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1103/PhysRevB.96.165311
DescriptionWe acknowledge the financial support by the European Research Council (ERC) Starting Grant PICSEN (grant no. 306387)
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