Cascaded emission of single photons from the biexciton in monolayered WSe2
Monolayers of transition metal dichalcogenide materials emerged as a new material class to study excitonic effects in solid state, as they benefit from enormous Coulomb correlations between electrons and holes. Especially in WSe 2 , sharp emission features have been observed at cryogenic temperature...
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Published in | Nature communications Vol. 7; no. 1; p. 13409 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
10.11.2016
Nature Publishing Group Nature Portfolio |
Subjects | |
Online Access | Get full text |
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Summary: | Monolayers of transition metal dichalcogenide materials emerged as a new material class to study excitonic effects in solid state, as they benefit from enormous Coulomb correlations between electrons and holes. Especially in WSe
2
, sharp emission features have been observed at cryogenic temperatures, which act as single photon sources. Tight exciton localization has been assumed to induce an anharmonic excitation spectrum; however, the evidence of the hypothesis, namely the demonstration of a localized biexciton, is elusive. Here we unambiguously demonstrate the existence of a localized biexciton in a monolayer of WSe
2
, which triggers an emission cascade of single photons. The biexciton is identified by its time-resolved photoluminescence, superlinearity and distinct polarization in micro-photoluminescence experiments. We evidence the cascaded nature of the emission process in a cross-correlation experiment, which yields a strong bunching behaviour. Our work paves the way to a new generation of quantum optics experiments with two-dimensional semiconductors.
Atomically thin transition metal dichalcogenides constitute an ideal platform to investigate solid state excitonic effects. Here, the authors provide experimental evidence of a localized biexciton in a monolayer of WSe
2
, which induces an emission cascade of single photons. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2041-1723 2041-1723 |
DOI: | 10.1038/ncomms13409 |