3 October 2016 Two-dimensional coherent spectroscopy of excitons, biexcitons, and exciton-polaritons
Author Affiliations +
Semiconductors systems exhibiting excitonic properties are discussed in terms of their coherent response, which is extracted using two-dimensional coherent spectroscopy. This control method allows for separation of quantum pathways that comprise the optical response, such as interactions between excitons, their dephasing rates, the effects of many-body interactions and the role of structure on the microscopic electronic environment. Additional controls, such as polarization can be used to further distinguish biexcitons and suppress many-body interactions. These result are compared and contrasted with those from a semiconductor microcavity where the excitons form polaritonic modes due to normal-mode splitting. Rephrasing spectra map the detuning dependence of the exciton-polariton branches. Increasing the detuning shifts all features to higher energy and the expected anti-crossing is observed. An isolated biexciton is seen only at negative detuning, separated by a binding energy. For positive detuning, the spectral weight of the off-diagonal features swap, as the lower polariton branch and biexciton come into resonance. This indicates that the off-diagonal features are sensitive to the interactions of the exciton-polaritons and other resonances in the system.
Conference Presentation
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Alan D. Bristow, Alan D. Bristow, "Two-dimensional coherent spectroscopy of excitons, biexcitons, and exciton-polaritons", Proc. SPIE 9956, Ultrafast Nonlinear Imaging and Spectroscopy IV, 99560Q (3 October 2016); doi: 10.1117/12.2236697; https://doi.org/10.1117/12.2236697

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