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Microscopic mechanism for transient population inversion and optical gain in graphene

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 نشر من قبل Torben Winzer
 تاريخ النشر 2012
  مجال البحث فيزياء
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A transient femtosecond population inversion in graphene was recently reported by Li et al., Phys. Rev. Lett. 108, 167401 (2012). Based on a microscopic theory we clarify the underlying microscopic mechanism: Transient gain and population inversion in graphene occurs due to a complex interplay of strong optical pumping and carrier cooling that fills states close to the Dirac point giving rise to a relaxation bottleneck. The subsequent femtosecond decay of the optical gain is mainly driven by Coulomb-induced Auger recombination.



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