Unconventional double-bended saturation of carrier occupation in optically excited graphene due to many-particle interactions
Artikel i vetenskaplig tidskrift, 2017

Saturation of carrier occupation in optically excited materials is a well-established phenomenon. However, so far, the observed saturation effects have always occurred in the strong-excitation regime and have been explained by Pauli blocking of the optically filled quantum states. On the basis of microscopic theory combined with ultrafast pump-probe experiments, we reveal a new low-intensity saturation regime in graphene that is purely based on many-particle scattering and not Pauli blocking. This results in an unconventional double-bended saturation behaviour: Both bendings separately follow the standard saturation model exhibiting two saturation fluences; however, the corresponding fluences differ by three orders of magnitude and have different physical origin. Our results demonstrate that this new and unexpected behaviour can be ascribed to an interplay between time-dependent many-particle scattering and phase-space filling effects.

Författare

T. Winzer

Technische Universität Berlin

M. Mittendorff

University of Maryland

S. Winnerl

Helmholtz-Zentrum Dresden-Rossendorf

Henry Mittenzwey

Technische Universität Berlin

Roland Jago

Chalmers, Fysik, Kondenserade materiens teori

Manfred Helm

Technische Universität Dresden

Helmholtz-Zentrum Dresden-Rossendorf

Ermin Malic

Chalmers, Fysik, Kondenserade materiens teori

Andreas Knorr

Technische Universität Berlin

Nature Communications

2041-1723 (ISSN)

Vol. 8 15042

Ämneskategorier

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

Styrkeområden

Materialvetenskap

DOI

10.1038/ncomms15042

PubMed

28485387