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arXiv · 2203.10295

Optical transitions, exciton radiative decay, and valley coherence in lead chalcogenide quantum dots

S. V. Goupalov·E. L. Ivchenko·M. O. Nestoklon
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Abstract

We propose the concept of valley coherence and superradiance in the reciprocal space and show that it leads to an $N$-fold decrease of the bright exciton radiative lifetime in quantum dots (QDs) of an $N$-valley semiconductor. Next we explain why, despite this, the exciton radiative lifetimes in PbX (X = S, Se, Te) QDs, measured from the photoluminescence decay, are in the microsecond range. We also address peculiarities of the light-matter interaction in nanostructures made of narrow-gap materials with strong inter-band coupling.

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S. V. Goupalov, E. L. Ivchenko, M. O. Nestoklon. 2022-03-19. Optical transitions, exciton radiative decay, and valley coherence in lead chalcogenide quantum dots. https://doi.org/10.1103/physrevb.106.125301

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