@article{HeIffLundtetal.2016,
  author    = {He, Yu-Ming and Iff, Oliver and Lundt, Nils and Baumann, Vasilij and Davanco, Marcelo and Srinivasan, Kartik and H{\"o}fling, Sven and Schneider, Christian},
  title     = {Cascaded emission of single photons from the biexciton in monolayered WSe\(_{2}\)},
  series = {Nature Communications},
  volume    = {7},
  journal   = {Nature Communications},
  doi       = {10.1038/ncomms13409},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169363},
  year      = {2016},
  abstract  = {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.},
  language  = {en}
}