Directly visualizing the momentum-forbidden dark excitons and their dynamics in atomically thin semiconductors

@article{Mado2020DirectlyVT,
  title={Directly visualizing the momentum-forbidden dark excitons and their dynamics in atomically thin semiconductors},
  author={Julien Mad{\'e}o and Michael K. L. Man and Chakradhar Sahoo and Marshall Campbell and Vivek Pareek and E. Laine Wong and Abdullah Al-Mahboob and Nicholas S. Chan and Arka Karmakar and Bala Murali Krishna Mariserla and Xiaoqin Li and Tony F. Heinz and Ting Cao and Keshav M. Dani},
  journal={Science},
  year={2020},
  volume={370},
  pages={1199 - 1204}
}
Probing the dark state Excitons, electron-hole pairs held together by Coulomb attraction, can be generated in semiconductors under excitation and greatly influence the material's optoelectronic properties. Although bright excitons are optically active, their dark-state cousins have been more difficult to detect. They do, however, affect the optoelectronic properties through their interaction with light and bright excitons. Madéo et al. developed a pump-probe photoemission technique that is used… 
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