Publications (13)
Review on carrier multiplication in graphene
Ermin Malic, Torben Winzer, Florian Wendler +1
The remarkable gapless and linear band structure of graphene opens up new carrier relaxation channels bridging the valence and the conduction band. These Auger scattering processes…
Impact of doping on the carrier dynamics in graphene
Faris Kadi, Torben Winzer, Andreas Knorr +1
We present a microscopic study on the impact of doping on the carrier dynamics in graphene, in particular focusing on its influence on the technologically relevant carrier multipli…
Impact of Auger processes on carrier dynamics in graphene
Torben Winzer, Ermin Malic
The linear, gapless bandstructure of graphene provides ideal conditions for Auger processes. They are of great importance for fundamental research and technological applications, s…
Carrier Multiplication in Graphene
Torben Winzer, Andreas Knorr, Ermin Malic
Graphene as a zero-bandgap semiconductor is an ideal model structure to study the carrier relaxation channels, which are inefficient in conventional semiconductors. In particular,…
Microscopic mechanism for transient population inversion and optical gain in graphene
Torben Winzer, Ermin Malic, Andreas Knorr
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 under…
Anisotropy of excitation and relaxation of photogenerated Dirac electrons in graphene
Martin Mittendorff, Torben Winzer, Ermin Malic +6
We investigate the polarization dependence of the carrier excitation and relaxation in epitaxial multilayer graphene. Degenerate pump-probe experiments with a temporal resolution o…
Stacking-dependent energetics and electronic structure of ultrathin polymorphic VVI topological insulator nanofilms
Can Li, Torben Winzer, Aron Walsh +3
Topological insulators represent a paradigm shift in surface physics. The most extensively studied BiSe-type topological insulators exhibit layered structures, wherein neig…
Graphene as Gain Medium for Broadband Lasers
Roland Jago, Torben Winzer, Andreas Knorr +1
In contrast to conventional structures, efficient non-radiative carrier recombination counteracts the appearance of optical gain in graphene. Based on a microscopic and fully quant…
Carrier dynamics in epitaxial graphene close to the Dirac point
Stephan Winnerl, Milan Orlita, Paulina Plochocka +10
We study the carrier dynamics in epitaxially grown graphene in the range of photon energies from 10 - 250 meV. The experiments complemented by microscopic modeling reveal that the…
Microscopic view on the ultrafast photoluminescence from photo-excited graphene
Torben Winzer, Richard Ciesielski, Matthias Handloser +3
We present a joint theory-experiment study on ultrafast photoluminescence from photoexcited graphene. Based on a microscopic theory, we reveal two distinct mechanisms behind the oc…
Unconventional double-bended saturation of optical transmission in graphene due to many-particle interactions
Torben Winzer, Martin Mittendorff, Stephan Winnerl +3
We present a joint theory-experiment study on the transmission/absorption saturation after ultrafast pulse excitation in graphene. We reveal an unconventional double-bended saturat…
Carrier dynamics in graphene: ultrafast many-particle phenomena
Ermin Malic, Torben Winzer, Florian Wendler +10
Graphene is an ideal material to study fundamental Coulomb- and phonon-induced carrier scattering processes. Its remarkable gapless and linear band structure opens up new carrier r…
Microscopic description of intraband absorption in graphene: the occurrence of transient negative differential transmission
Faris Kadi, Torben Winzer, Ermin Malic +1
We present a microscopic explanation of the controversially discussed transient negative differential transmission observed in degenerate optical pump-probe measurements in graphen…